Forget (Some of) What You Know About Runners on Third
I’ll spare you the description of how I came up with the idea for this article. There was a lot of Alex Rodriguez’s announcing involved, and this is a family website, so my opinions on that will remain undiscussed. The point is, though, that it made me wonder about something I used to take for granted but have increasingly questioned: how do pitchers change their game plan with a runner on third base?
Depending on who you talk to, it might matter a lot or a little. Maybe pitchers won’t be willing to bounce one. Maybe they’ll pitch to a strikeout (assuming fewer than two outs), trying to keep the run from scoring. Maybe pitchers will completely ignore the runner on third and pitch normally. I’m legitimately uncertain. Not I think it’s 50% likely to be one and 50% likely to be the other — I have absolutely no idea how to weigh the relevant probabilities.
First things first; what about those bounced pitches? This is a classic announcer trope, but it’s a trope for a reason; throwing a pitch in the dirt really is more dangerous with a runner on third. Through the magic of run expectancy tables, we can see how much a one-base advancement costs the fielding team, based on whether there’s a runner on first, second, or third (I ignored other base/out states for brevity’s sake):
Runner On | 0 Out | 1 Out | 2 Out |
---|---|---|---|
1 | 0.21 | 0.15 | 0.10 |
2 | 0.22 | 0.24 | 0.05 |
3 | 0.18 | 0.35 | 0.72 |
With no one out, everything is more or less the same; that runner on third was pretty likely to score anyway, in fact. As the outs pile up, allowing the runner from third to score hurts more and more — quite logical. Read the rest of this entry »