Importance Of Starting Pitching

May 27, 2009 – 4:56 pm

After last night’s game I got to thinking about how important it is for the starter to get through at least 6 innings, and so cobbled up some stats showing what the W/L percentage is based on how many innings the starter went:

W/L By Innings Pitched By Starter
American League Yankees
IP W L W Pct. IP W L W Pct.
1 2 8 20% 1 0 3 0%
2 2 9 18% 2 0 0 0%
3 10 26 28% 3 0 1 0%
4 10 47 18% 4 1 3 25%
5 67 85 44% 5 4 4 50%
6 103 85 55% 6 8 6 57%
7 85 40 68% 7 8 1 89%
8 26 19 58% 8 3 2 60%
9 13 0 100% 9 1 0 100%

Overall this pretty much confirms what you probably already figured — that the “sweet spot” is 6 innings. Anything less than 6 innings from the starter, the odds of you winning are less than 50%. And as you might expect, getting 7 innings from the starter is even better, increasing the win probability to 68%. However, there’s an interesting dip in the chart at 8 innings completed. It would seem that you are actually better off going to the bullpen after 7 rather than pushing the starter one more inning. If you think about it, though, this makes sense — in today’s world, starters rarely are asked to go more than 7 innings and so trying to complete the 8th is probably pushing them physically.

Even though the sample sizes are pretty small, the Yankees pretty much follow the trend here, with slightly higher win percentages the more innings the starter goes. Which is what you would figure, given how weak the Yankee bullpen is.

Sorry, comments for this entry are closed at this time.