Thursday, May 26, 2011

Finer Points of "Losing" vs. "Winless" Streaks for Baseball Pitchers

When evaluating the magnitude of a given streak, it is important to consider the streak's precise definition. Rarely is such attention to detail more important than in the current pitching struggles of Toronto's Jo-Jo Reyes. During Reyes's skid, his official win-loss record has been 0-13, far short Anthony Young's mark of 0-27 during stretches of the 1992 and 1993 seasons. Yet, Reyes is taking plenty of grief in the sports media.

The key to understanding the attention being garnered by Reyes, in my view, is the fact that pitching wins and losses are not exhaustive categories. In other words, a pitcher can be credited not only with a win or loss for a given stint on the mound, but also a no-decision (other categories, such as save and hold, are available for relief appearances). If we say a pitcher has a "losing streak," we're talking about repeatedly getting an actual "L" on the scorecard. If we say that a pitcher has a "winless streak," on the other hand, we're talking about all outcomes other than a "W," primarily L's or no-decisions.

Young's streak was a losing streak -- the number of consecutive times he received a loss decision in games where he got some kind of official W-or-L decision. By this definition, he lost 27 consecutive games.

In Reyes's case, his dubious achievement consists of starting 28 consecutive games and not coming away with a win in any of them -- in other words, a winless streak. This length of winless streak is a major-league record, which Reyes now shares with two other pitchers. By failing to win in his next start (if Toronto will start him anymore), Reyes would hold the record all by himself. As noted above, Reyes has a win-loss record of 0-13 during his streak, but in theory, it could be 0-0 if he had 28 straight no-decisions.

I have created the graph below with the aim of clarifying the situation. It shows all of Young's and Reyes's pitching appearances (in many of which they were sent to the showers) during their respective streaks. You may click on the graph to enlarge it.

The data come from the website Baseball Reference (Young 1992, 1993; Reyes 2008, 2009, 2010, 2011).

Young's 27 losses fell within the scope of 79 consecutive games he pitched, spanning two seasons, in which he never achieved a win. As can be seen, he had a bunch of no-decisions and, on a positive note, some saves in a relief role. There clearly were games during the losing streak during which Young pitched well and easily could have gotten a win with better luck (here and here). But with a starting hurler's prospects for a win or a loss partially under the control of the hitters and relief pitchers on his team, a good showing on the mound isn't necessarily enough for a win.

Early in Reyes's streak, he suffered a string of five losses in five starts. Ever since, his losses have tended to come not in bunches, but sporadically, amidst large numbers of no-decisions.

What to conclude about these two pitchers? In Young's favor, his loss total during his doldrums tells us that he was the pitcher of record when the opposing team scored its winning run(s) about a third of the time (27/79), whereas for Reyes, the figure is nearly one-half (13/28 starts). Also, whereas Young did not achieve any wins during his streak, he did achieve the objective his team gave him -- holding or saving a lead -- during some of his relief appearances.

Because of his predominant role of starter, Reyes cannot be said to have achieved his and his team's objective of winning games; he may have successfully kept his team in contention some of the time, however.

Further parameters, such as each pitcher's actual numbers of earned runs allowed and run support from his teammates, are necessary for a more complete evaluation of what happened with Young and what is currently going on with Reyes. However, such elements are beyond the scope of the current posting and will need to be revisited later.


Fittingly for an NBA playoff season that has featured many dramatic scoring runs, the Miami Heat outscored Chicago 18-3 over the final three minutes Thursday night to edge the Bulls, 83-80, and capture the Eastern Conference finals in five games.

No comments: