Monday, May 27, 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.

Saturday, May 25, 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).

Monday, May 20, 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.

Friday, May 03, 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