Watch any Yankee game on the YES Network and sooner or later Mr. Kay will mention stolen bases against Dellin Betances. Since there are no secrets in baseball statistics, the figures are there for the taking. And yes, Betances has allowed eighteen stolen bases in eighteen attempts. That's bad. Opposing teams know this and will exploit any weakness and thus will run and run and run on the big guy. But does it matter in the big picture of things? Yes and no.
The eighteen stolen bases have all come in fifteen of Bantances' 62 appearances and in seventeen of his 63.2 innings pitched. That works out to 27% of his innings pitched and 24% of his appearances. The rest of the time, he is too busy striking out people and limiting men on base. But Betances is not perfect and base runners will occur at least occasionally.
The good news is that Betances actually has a better run scored average against him when he allows steals than when he doesn't. I am talking all runs here whether earned or not because it is a relief pitcher's job not to allow runs to occur.
In all of Betances' appearances, he has allowed 2.58 runs to score per nine innings good for a 2.12 ERA. In games where he has allowed a stolen base (three times, he has allowed 2 SBs), his runs allowed per nine innings is 2.11 or four runs on his 18 base runners in seventeen innings. In games where he does not allow a stolen base, his runs allowed per nine are much worse at 2.74.
That is the good news.
The good news is that his base steals allowed do not greatly affect his runs allowed on his own base runners. The bad news is that they are killers for his teammates' ERA. For the season, Dellin Betances has allowed seven of his twenty inherited runners to score. That is 35%--a bit higher than the league average of 27%.
The real eye-opener is that when a stolen base is involved, six of his inherited nine base runners have scored. That is 67%. Ouch! When he inherits runners and there is no stolen base, then only one of his eleven inherited runners scored. The stolen base really increased the odds those inherited runners would score.
In the fifteen games where Betances has allowed a stolen base, he has one win, one loss, six holds, one save and two blown saves. The two blown saves account for half of his total for all of 2016. In other words, half of his blown saves have occurred in 24% of his appearances where he has allowed a stolen base.
The bottom line is that the success base runners have stealing on Dellin Betances does matter and has contributed perhaps to at least three losses this season. On the other hand, the big dude has also saved seven games and has an 0.974 WHIP while adding another 27 Holds and three wins. It is one of those things where the good far outweighs the bad.
What this means for the Yankees is that perhaps Joe Girardi should consider not waiting until a base runner is on first before bringing Betances in the game and would be better served to just let Betances start the inning. And perhaps the good so far outweighs the bad that you simply accept it for what it is.