Double Play
Two outs on one batted ball, and the single most damaging thing that can happen to an offense in one pitch.
What it actually is. A double play is any play that records two outs on one continuous action. The most common shape is a ground ball with a man on first, fielded and thrown to second to force him and on to first to get the batter, written 6-4-3 or 4-6-3 by position numbers. A line drive caught with a runner off the bag and doubled off is also one.
What somebody who knows the game gets out of it. The double play is the reason the ground ball is the defense's friend and the reason left handed hitters have a small structural advantage on it, since they start a step closer to first. Its real cost is best read in run expectancy terms: a man on first with nobody out is worth about .85 runs, and a double play turns that into nobody on with two out, worth about .10, which makes it about a three quarters of a run swing on one pitch. Nothing else routine is that expensive.
The numbers worth knowing. A team grounds into roughly 100 double plays over a season and turns a similar number. A slow right handed hitter with a high ground ball rate can ground into 25 or more.
What people get wrong about it. Grounding into double plays is only partly a hitter's fault, because it requires a man on first and fewer than two out, and how often that happens is a fact about the men in front of him. The rate per opportunity is the number worth looking at, not the raw total. The slide rule also matters here: since 2016 a runner has to make a bona fide slide at second and cannot go out of the baseline to break up the pivot.
At Little League and travel ball. Double plays are rare at youth level and are usually given away rather than turned, because the pivot at second is a hard skill and the throw is long. What is worth drilling instead is the sure out: a 12U infield that reliably gets one is ahead of one that attempts two and gets none. Read the Play on this site covers the footwork for both.
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