The Chicago Blackhawks' Stanley Cup-clinching win tonight creates a hockey parallel with last week's NBA championship by the Miami Heat. The teams' shared feat is capping off a regular season notable for a long winning/unbeaten streak with a league championship.
The Heat, of course, had a 27-game winning streak during the regular season, the second-longest in league history and the longest since the L.A. Lakers won 33 straight, 41 years earlier.
Similarly, the Hawks enjoyed a lengthy streak this year, opening the lockout-shortened NHL season on a spurt of 24 straight games without a regulation-time loss. During this stretch, Chicago had 14 regulation-time wins, seven overtime/shoot-out wins, and three shoot-out losses.
lunes, 24 de junio de 2013
lunes, 17 de junio de 2013
Trying to Close Out an NBA Final Series on the Road After Winning Game 5 at Home to Go Up 3-2
With last night's Game-5 victory over the Miami Heat to take a 3-2 series lead, the San Antonio Spurs now need only a single victory to claim the NBA crown. However, Tuesday's Game 6 and (if necessary) Thursday's Game 7 will be played in Miami. Thus, the Spurs have the momentum, whereas the Heat has the home court. How much are these respective, putative advantages worth in an NBA final series?
The sample size of historical NBA finals matching the circumstances of this year's Heat-Spurs match-up is small. Still, let's take a look at similar series over the years. It should first be noted that the current 2-3-2 finals format (i.e., two games at the home of the team with the better regular-season record, the next three games at the opponent's home, and the final two back in the first city) began with the finals of the 1984-85 season. Here are the final series since then in which a team has won Game 5 (abbreviated "G5") at home to take a 3-2 lead, and then sought to win the title on the road (data from here).
As seen in the table, it's a wash: Three teams (shown in red) used their home Game-5 victory as a springboard to close out the series on the road in six games, whereas another three Game-5 winners at home (shown in blue) never got the clinching fourth win.
Two Michael Jordan-era Chicago Bulls squads entered a road Game 6 with a 3-2 lead in the finals and won the title in six, both times. However, those two experiences -- vs. Phoenix in 1992-93 and vs. Utah in 1997-98 -- are different from those in the table above. In both cases, the Bulls had led 3-1 and failed to close out the series at home in five.
We can expand the database by looking at years prior to the switch to 2-3-2, in which a 2-2-1-1-1 format (usually) was used for the finals. Under this format, a team that won Game 5 at home to go ahead 3-2 had the opportunity to wrap up the series on the road in Game 6 (although the home team for Game 5 knew that it would also play Game 7 at home, if necessary). Staying within the past 50 years, there were eight series in which a team won Game 5 at home to take a 3-2 lead and then went on the road for Game 6 (but not Game 7). They are as follows.
*Winner of Game 5 won Game 7 back at home.
Again, it's a wash. Four teams (shown in dark green) won Game 5 at home to take a 3-2 lead and then captured the title on the road in Game 6. However, another four similarly situated teams (shown in orange) failed to do so.
If we assume that a road team in basketball usually has less than a 50/50 probability of winning, then the fact that a team that won Game 5 at home to take a 3-2 lead won Game 6 on the road 50% of the time in the above years suggests that there may be something to the notion of momentum in this context. There's a (somewhat) complicating factor, however. With the 2-2-1-1-1 format (prior to 1984-85), the road team in Game 6 would have been the team with the better regular-season record and thus arguably the better team. That may be why Game-5 winners may have done well in Game-6 road contests, as much or more so than benefiting from momentum.
In the 2-3-2 era, in contrast, the road team in Game 6 would be the one with the worse regular-season record. Hence, a 50% success rate for such teams in Game 6 speaks well for momentum.
The sample size of historical NBA finals matching the circumstances of this year's Heat-Spurs match-up is small. Still, let's take a look at similar series over the years. It should first be noted that the current 2-3-2 finals format (i.e., two games at the home of the team with the better regular-season record, the next three games at the opponent's home, and the final two back in the first city) began with the finals of the 1984-85 season. Here are the final series since then in which a team has won Game 5 (abbreviated "G5") at home to take a 3-2 lead, and then sought to win the title on the road (data from here).
| Year | Won G5 @ Home | Opponent | Series Outcome |
| 1984-85 | Lakers | Celtics | Lakers in 6 |
| 1987-88 | Pistons | Lakers | Lakers in 7 |
| 1993-94 | Knicks | Rockets | Rockets in 7 |
| 2005-06 | Heat | Mavericks | Heat in 6 |
| 2009-10 | Celtics | Lakers | Lakers in 7 |
| 2010-11 | Mavericks | Heat | Mavericks in 6 |
As seen in the table, it's a wash: Three teams (shown in red) used their home Game-5 victory as a springboard to close out the series on the road in six games, whereas another three Game-5 winners at home (shown in blue) never got the clinching fourth win.
Two Michael Jordan-era Chicago Bulls squads entered a road Game 6 with a 3-2 lead in the finals and won the title in six, both times. However, those two experiences -- vs. Phoenix in 1992-93 and vs. Utah in 1997-98 -- are different from those in the table above. In both cases, the Bulls had led 3-1 and failed to close out the series at home in five.
We can expand the database by looking at years prior to the switch to 2-3-2, in which a 2-2-1-1-1 format (usually) was used for the finals. Under this format, a team that won Game 5 at home to go ahead 3-2 had the opportunity to wrap up the series on the road in Game 6 (although the home team for Game 5 knew that it would also play Game 7 at home, if necessary). Staying within the past 50 years, there were eight series in which a team won Game 5 at home to take a 3-2 lead and then went on the road for Game 6 (but not Game 7). They are as follows.
| Year | Won G5 @ Home | Opponent | Won G6 on Road? |
| 1967-68 | Celtics | Lakers | Yes |
| 1968-69 | Lakers | Celtics | No |
| 1969-70 | Knicks | Lakers | No* |
| 1975-76 | Celtics | Suns | Yes |
| 1977-78 | Supersonics | Bullets (Wizards) | No |
| 1979-80 | Lakers | 76ers | Yes |
| 1980-81 | Celtics | Rockets | Yes |
| 1983-84 | Celtics | Lakers | No* |
Again, it's a wash. Four teams (shown in dark green) won Game 5 at home to take a 3-2 lead and then captured the title on the road in Game 6. However, another four similarly situated teams (shown in orange) failed to do so.
If we assume that a road team in basketball usually has less than a 50/50 probability of winning, then the fact that a team that won Game 5 at home to take a 3-2 lead won Game 6 on the road 50% of the time in the above years suggests that there may be something to the notion of momentum in this context. There's a (somewhat) complicating factor, however. With the 2-2-1-1-1 format (prior to 1984-85), the road team in Game 6 would have been the team with the better regular-season record and thus arguably the better team. That may be why Game-5 winners may have done well in Game-6 road contests, as much or more so than benefiting from momentum.
In the 2-3-2 era, in contrast, the road team in Game 6 would be the one with the worse regular-season record. Hence, a 50% success rate for such teams in Game 6 speaks well for momentum.
viernes, 7 de junio de 2013
Serena Williams's Tennis Winning Streak
See update after 2015 Australian Open.
Serena Williams brings a career-best 30-match winning streak into tomorrow's women's singles final of the French Open -- and a 12-match winning streak in head-to-head matches against her opponent tomorrow, Maria Sharapova. Williams presumably will be a heavy favorite to win this Grand Slam event, but even if we just look at what she has accomplished in the last few months of non-Grand Slam tournaments, it's still pretty remarkable.
First, Williams is a power player, with the New York Times quoting multiple experts that her serve is the best ever in the women's game. Yet, her 30-match winning streak has occurred mostly on clay, a surface that slows the ball down. In fact, of Williams's 15 Grand Slam titles to date, only one has come at the French Open (2002), which is played on clay. The other 14 have come at the Australian Open, Wimbledon (All-England), and U.S. Open championships, which are played on faster surfaces.
Second, Williams is currently 31 years old, a seemingly advanced age at which to embark on a career-longest winning streak. The study of baseball statistics ("sabermetrics") has produced "age curves" of players' productivity over time. I was not familiar with age curves for tennis, so I created a rough estimate of them for seven all-time great women's tennis players: Serena and her sister Venus Williams, Margaret Court, Billie Jean King, Chris Evert, Martina Navratilova, and Steffi Graf. You may click on the following graphic to enlarge it.
To arrive at these players' ages at which they won Grand Slam tournaments, I compared their dates of birth to these rough guidelines of when the finals of the four tourneys are held: Australian, early January; French, early June; Wimbledon, early-mid July; and U.S. Open, early September. The Australian Open has switched back-and-forth between December and January, but I used January throughout my analyses. Thus, it's quite possible that I could be off a year on some of these players' ages.
The main finding appears to be that most of the great women's tennis players of the modern era have tended to tail off beginning in their late twenties. Serena, in contrast, had some (relatively) lean years in her mid-twenties (three Grand Slam titles in the five years from ages 22-26), before experiencing a renaissance from ages 27-30 (six titles in four years).
As far as Serena's current 30-match win streak, she is still quite a ways from the top five women's winning streaks (Evert holds the fifth-longest streak at 55 straight wins), let alone the longest women's winning streak of all time, 74 matches by Navratilova. (A list of the longest women's tennis winning streaks, as of March 2012, is available here.)
The way Williams is playing, and with the upcoming switch to grass-court tournaments leading up to Wimbledon, I wouldn't rule out anything for her.
Serena Williams brings a career-best 30-match winning streak into tomorrow's women's singles final of the French Open -- and a 12-match winning streak in head-to-head matches against her opponent tomorrow, Maria Sharapova. Williams presumably will be a heavy favorite to win this Grand Slam event, but even if we just look at what she has accomplished in the last few months of non-Grand Slam tournaments, it's still pretty remarkable.
First, Williams is a power player, with the New York Times quoting multiple experts that her serve is the best ever in the women's game. Yet, her 30-match winning streak has occurred mostly on clay, a surface that slows the ball down. In fact, of Williams's 15 Grand Slam titles to date, only one has come at the French Open (2002), which is played on clay. The other 14 have come at the Australian Open, Wimbledon (All-England), and U.S. Open championships, which are played on faster surfaces.
Second, Williams is currently 31 years old, a seemingly advanced age at which to embark on a career-longest winning streak. The study of baseball statistics ("sabermetrics") has produced "age curves" of players' productivity over time. I was not familiar with age curves for tennis, so I created a rough estimate of them for seven all-time great women's tennis players: Serena and her sister Venus Williams, Margaret Court, Billie Jean King, Chris Evert, Martina Navratilova, and Steffi Graf. You may click on the following graphic to enlarge it.
To arrive at these players' ages at which they won Grand Slam tournaments, I compared their dates of birth to these rough guidelines of when the finals of the four tourneys are held: Australian, early January; French, early June; Wimbledon, early-mid July; and U.S. Open, early September. The Australian Open has switched back-and-forth between December and January, but I used January throughout my analyses. Thus, it's quite possible that I could be off a year on some of these players' ages.
The main finding appears to be that most of the great women's tennis players of the modern era have tended to tail off beginning in their late twenties. Serena, in contrast, had some (relatively) lean years in her mid-twenties (three Grand Slam titles in the five years from ages 22-26), before experiencing a renaissance from ages 27-30 (six titles in four years).
As far as Serena's current 30-match win streak, she is still quite a ways from the top five women's winning streaks (Evert holds the fifth-longest streak at 55 straight wins), let alone the longest women's winning streak of all time, 74 matches by Navratilova. (A list of the longest women's tennis winning streaks, as of March 2012, is available here.)
The way Williams is playing, and with the upcoming switch to grass-court tournaments leading up to Wimbledon, I wouldn't rule out anything for her.
lunes, 27 de mayo de 2013
Haase Wins Tie-Break in French, Finally Ends Streak
Following up on an earlier posting, Dutch tennis player Robin Haase finally ended his tie-breaker losing streak, which had reached 17 (under the policy of excluding anything that occurred in a qualifying-round match). Playing in the first round of the French Open against Kenny De Schepper of France, Haase prevailed in a tie-breaker at the end of the second set, by a 7-3 score; Haase also prevailed in the match as a whole, three sets to one.
sábado, 25 de mayo de 2013
A Look Back at Kevin Durant's Playoff FT Shooting
His Oklahoma City Thunder squad was eliminated in the second round of the NBA playoffs by Memphis, but Kevin Durant's postseason free-throw shooting showed an interesting trend that I thought might be of some interest.
Durant first crossed my radar screen early in his career, specifically when he played against Texas Tech in Lubbock as a University of Texas freshman in 2007. Standing 6-foot-9 and sporting a deadly three-point shot, Durant fits into what one sportswriter calls the "Stretch 4" category of big guys who can shoot from outside.
Durant is a career .884 free-throw shooter as a pro. During the 2012-13 NBA regular season, he was even better at .905. As shown in the following graph depicting each OKC playoff game this year, Durant's shooting from the stripe continued at this lofty level, for the most part. The team's free-throw percentages track with Durant's, in part because Durant gets a large share of the team's attempts, but also because Thunder players generally are good from the line. (You may click on the graphic to enlarge it.)
As can be seen, however, Durant's free-throw accuracy dipped in the final three games against Memphis. In his first eight playoff games (all six against Houston and the first two vs. Memphis), Durant never fell below .800 in any individual contest; cumulatively in these first eight games, he shot .882 (75/85). In Durant's (and the Thunder's) final three games, in contrast, he never reached .800 in any contest and shot a cumulative .667 (18/27).
Just a blip? Possibly. Fatigue? Maybe. One could do a statistical comparison of Durant in his first eight vs. his last three playoff games. However, most statisticians would probably consider such a test to be "cherry-picking" (deciding to conduct a test only after seeing a sharp drop in Durant's free-throw accuracy).
Durant first crossed my radar screen early in his career, specifically when he played against Texas Tech in Lubbock as a University of Texas freshman in 2007. Standing 6-foot-9 and sporting a deadly three-point shot, Durant fits into what one sportswriter calls the "Stretch 4" category of big guys who can shoot from outside.
Durant is a career .884 free-throw shooter as a pro. During the 2012-13 NBA regular season, he was even better at .905. As shown in the following graph depicting each OKC playoff game this year, Durant's shooting from the stripe continued at this lofty level, for the most part. The team's free-throw percentages track with Durant's, in part because Durant gets a large share of the team's attempts, but also because Thunder players generally are good from the line. (You may click on the graphic to enlarge it.)
As can be seen, however, Durant's free-throw accuracy dipped in the final three games against Memphis. In his first eight playoff games (all six against Houston and the first two vs. Memphis), Durant never fell below .800 in any individual contest; cumulatively in these first eight games, he shot .882 (75/85). In Durant's (and the Thunder's) final three games, in contrast, he never reached .800 in any contest and shot a cumulative .667 (18/27).
Just a blip? Possibly. Fatigue? Maybe. One could do a statistical comparison of Durant in his first eight vs. his last three playoff games. However, most statisticians would probably consider such a test to be "cherry-picking" (deciding to conduct a test only after seeing a sharp drop in Durant's free-throw accuracy).
lunes, 20 de mayo de 2013
Lionel Messi's Recent Soccer Scoring Streak in Spain
Lionel (Leo) Messi, an Argentinian who plays in Spain for FC Barcelona in the Spanish football/soccer league ("La Liga"), had his 21-game goal-scoring streak ended on May 12. According to this article: "His streak of scoring in his last 21 consecutive league games started on 11th November last year, in an away league match against Mallorca, where he scored 2 goals. With no goal from Leo today, the longest-ever streak of scoring in a league ended."
The same article lists how many goals Messi scored in each of the 21 games during the streak. For the first six games of the streak, he scored two goals (known as a "brace") in each outing. He scored one goal in each of the next four games, then erupted for four goals in a January 27 game against Osasuna. In the final 10 games of the streak, Messi scored a single goal seven times and a brace three times. All told, he scored 33 goals during the streak, 1.57 per game.
Probably like most U.S. sports fans, I get most of my exposure to international soccer through the quadrennial World Cup. I recall that the 2010 World Cup had many 1-0 scores, which made me wonder if goals were similarly rare in La Liga. If so, Messi would not only be a great soccer player, but also a miracle worker.
Looking at FC Barcelona's 2012-13 game-by-game log (with La Liga contests denoted by a color-wheel logo and the word "league"), the team has averaged 3.03 goals in league games, as of this writing (109 goals in 36 games). Thus, whether it's the relative abilities of offensive and defensive players or the style of play, La Liga appears much more conducive to scoring than World Cup competition.
Don't get me wrong. Even in an apparently offense-friendly league, what Messi has done is unprecedented -- by a wide margin, as the previous La Liga consecutive scoring record was 10 games. Also, as noted in the linked article in the previous paragraph, Messi also has set a scoring record when competing for Argentina in international play, so his scoring ability clearly transcends any particular league.
The same article lists how many goals Messi scored in each of the 21 games during the streak. For the first six games of the streak, he scored two goals (known as a "brace") in each outing. He scored one goal in each of the next four games, then erupted for four goals in a January 27 game against Osasuna. In the final 10 games of the streak, Messi scored a single goal seven times and a brace three times. All told, he scored 33 goals during the streak, 1.57 per game.
Probably like most U.S. sports fans, I get most of my exposure to international soccer through the quadrennial World Cup. I recall that the 2010 World Cup had many 1-0 scores, which made me wonder if goals were similarly rare in La Liga. If so, Messi would not only be a great soccer player, but also a miracle worker.
Looking at FC Barcelona's 2012-13 game-by-game log (with La Liga contests denoted by a color-wheel logo and the word "league"), the team has averaged 3.03 goals in league games, as of this writing (109 goals in 36 games). Thus, whether it's the relative abilities of offensive and defensive players or the style of play, La Liga appears much more conducive to scoring than World Cup competition.
Don't get me wrong. Even in an apparently offense-friendly league, what Messi has done is unprecedented -- by a wide margin, as the previous La Liga consecutive scoring record was 10 games. Also, as noted in the linked article in the previous paragraph, Messi also has set a scoring record when competing for Argentina in international play, so his scoring ability clearly transcends any particular league.
viernes, 3 de mayo de 2013
12 (Or Is It 14?) Straight Tie-Breakers Lost by Haase
This development is a little old, but I only noticed it today. Jeff Sackmann wrote on April 12 at his "Heavy Topspin" tennis website that men's pro Robin Haase had lost 13 consecutive tie-breakers. According to Sackmann:
No other active player has a streak of more than seven, and no tour-level regular has lost more than his last six. In fact, Haase is now one lost tiebreak away from tying the all-time ATP [Association of Tennis Professionals] record of 14, jointly held by Graham Stilwell and Colin Dibley, two players who accomplished their feats in the 1970s.
With a 1-6, 6-2, 6-7 loss to Pablo Carreno-Busta on April 22, Haase has, in fact, now technically tied the record of 14 straight lost tie-breakers. Why do I say "technically"? If one peruses the ATP World Tour website for Haase's results, starting with the most recent ones and working backwards in time, one counts "only" 12 lost tie-breaks before noticing a breaker that he won. This win by Haase occurred on May 13, 2012 at the ATP World Tour Masters in Rome, as he beat Sergiy Stakhovsky, 6-4, 7-6 (11-9). Prior to winning that tie-breaker, Haase had lost his two previous ones.
The reason Haase's streak is officially listed as being 14, Sackmann has confirmed, is that the tie-breaker Haase won over Stakhovsky occurred in a qualifying-round match (note the "Q1" on the ATP site), not the tournament draw proper. If the ATP's policy has always been that only main-draw matches count for record purposes, so be it. Perhaps the thinking is that, because the level of competition presumably is less demanding in the qualifying rounds than in the main draw, only the latter should be counted for record purposes. Let's be clear, though: Whether one considers Haase's tie-breaker losing streak to be 12 or 14, it's unusually long in either case!
The reason I was looking up all of Haase's matches, in the first place, is that I was curious with regards to how many points he was garnering in the tie-breakers during his stretch of futility. Has he been getting blown out in them (e.g., 7-0, 7-1, 7-2)? That might suggest a major freeze-up. Or, on the other hand, has he been taking his opponents to the wire, losing the tie-breakers by the minimum two points (e.g., 7-5, 8-6, 9-7)? If the latter, Haase wouldn't be experiencing full implosion at the umpire's call of "Games are tied at 6-all," but one would still have to wonder why he consistently lost close tie-breakers. I created the following graph to show Haase's frequency of different point totals in tie-breakers during his losing streak.
The picture is mixed, yielding what statisticians call a bimodal distribution (i.e., two values tied for being most frequent). Five times, Haase was blown out 7-2, whereas he lost another tie-break 7-3. However, he has also stayed within two points on five occasions, losing 7-5 (twice) or 8-6 (thrice).
Sackmann has done extensive research on the likelihood of winning tie-breakers, which you can find by following the links in his various Heavy Topspin postings (e.g., here). Sackmann has developed formulas for how many tie-breaks a given player would be expected to win, given the player's success for entire matches at winning points on serve and receiving. Players with better-than-average skills should win more than 50% of tie-breakers, whereas those with less-stellar skills should win fewer. Sackmann finds that, "Aside from a small minority of players with extensive tiebreak experience (such as Roger Federer, John Isner, and Andy Roddick), ATP pros tend to win about as many breakers as 'expected.'"
Obviously, Haase has been an outlier on the unfavorable end. Interested readers can readily follow Haase's match-by-match results, to find out if/when his streak of lost tie-breakers ends. As noted above, the ATP website has Haase's results available. Sackmann also provides frequent Twitter updates on major tennis developments, including Haase's streak
No other active player has a streak of more than seven, and no tour-level regular has lost more than his last six. In fact, Haase is now one lost tiebreak away from tying the all-time ATP [Association of Tennis Professionals] record of 14, jointly held by Graham Stilwell and Colin Dibley, two players who accomplished their feats in the 1970s.
With a 1-6, 6-2, 6-7 loss to Pablo Carreno-Busta on April 22, Haase has, in fact, now technically tied the record of 14 straight lost tie-breakers. Why do I say "technically"? If one peruses the ATP World Tour website for Haase's results, starting with the most recent ones and working backwards in time, one counts "only" 12 lost tie-breaks before noticing a breaker that he won. This win by Haase occurred on May 13, 2012 at the ATP World Tour Masters in Rome, as he beat Sergiy Stakhovsky, 6-4, 7-6 (11-9). Prior to winning that tie-breaker, Haase had lost his two previous ones.
The reason Haase's streak is officially listed as being 14, Sackmann has confirmed, is that the tie-breaker Haase won over Stakhovsky occurred in a qualifying-round match (note the "Q1" on the ATP site), not the tournament draw proper. If the ATP's policy has always been that only main-draw matches count for record purposes, so be it. Perhaps the thinking is that, because the level of competition presumably is less demanding in the qualifying rounds than in the main draw, only the latter should be counted for record purposes. Let's be clear, though: Whether one considers Haase's tie-breaker losing streak to be 12 or 14, it's unusually long in either case!
The reason I was looking up all of Haase's matches, in the first place, is that I was curious with regards to how many points he was garnering in the tie-breakers during his stretch of futility. Has he been getting blown out in them (e.g., 7-0, 7-1, 7-2)? That might suggest a major freeze-up. Or, on the other hand, has he been taking his opponents to the wire, losing the tie-breakers by the minimum two points (e.g., 7-5, 8-6, 9-7)? If the latter, Haase wouldn't be experiencing full implosion at the umpire's call of "Games are tied at 6-all," but one would still have to wonder why he consistently lost close tie-breakers. I created the following graph to show Haase's frequency of different point totals in tie-breakers during his losing streak.
The picture is mixed, yielding what statisticians call a bimodal distribution (i.e., two values tied for being most frequent). Five times, Haase was blown out 7-2, whereas he lost another tie-break 7-3. However, he has also stayed within two points on five occasions, losing 7-5 (twice) or 8-6 (thrice).
Sackmann has done extensive research on the likelihood of winning tie-breakers, which you can find by following the links in his various Heavy Topspin postings (e.g., here). Sackmann has developed formulas for how many tie-breaks a given player would be expected to win, given the player's success for entire matches at winning points on serve and receiving. Players with better-than-average skills should win more than 50% of tie-breakers, whereas those with less-stellar skills should win fewer. Sackmann finds that, "Aside from a small minority of players with extensive tiebreak experience (such as Roger Federer, John Isner, and Andy Roddick), ATP pros tend to win about as many breakers as 'expected.'"
Obviously, Haase has been an outlier on the unfavorable end. Interested readers can readily follow Haase's match-by-match results, to find out if/when his streak of lost tie-breakers ends. As noted above, the ATP website has Haase's results available. Sackmann also provides frequent Twitter updates on major tennis developments, including Haase's streak
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