Going deep: Jered Weaver's "dead arm" comment

After Jered Weaver had his third straight sub-par outing in May on Friday in Texas, he alluded to a potential explanation, saying,"I don't know if it's a matter of a little dead arm or whatnot."

It certainly looks like a lot more "what," than, "not," with Weaver's velocity apparently dipping slightly, but significantly, and his off-speed pitches tending to hang up in the zone.

Entering tonight's start against the Seattle Mariners, Weaver's season has hit the brakes in a dramatic way:

He was 6-0 with a 0.99 ERA in April. He's 0-3 with a 5.50 ERA in May.

Batters hit .163 off him last month, they're hitting .274 off him this month. His WHIP was 0.79 that month. It's 1.53 this month. He struck out 9.7 batters per nine innings then and he's striking out 6.0 per nine now.

We asked our ESPN Stats and Info department to dig a little deeper and here's the conclusion researcher Hank Gargiulo came up with: Maybe he's just not getting as lucky.

Start with the fact that the batting average on balls put in play against Weaver in April was .220. It's .300 this month. Those numbers don't necessarily mean it's all luck, but they hint at it.

Here's what Gargiulo says:

"Jered Weaver's dominant April might have been aided by a bit of good luck, and he might just be regressing to the mean in May. Weaver has also faced three of the top four hitting teams in the American League in May. His approach has been similar, though. He is throwing about the same number of strikes (64.8% to 64.0%), about the same number of pitches in the strike zone (46.8% to 45.9%) and getting opposing hitters to chase about the same percentage (31.5% to 31.1%).

The big difference looks to be his ability to get opposing hitters to swing and miss at pitches inside the strike zone. His miss percentage on pitches in the strike zone has fallen from 19.7% in April to 11.5% in May. His biggest drop has come in pitches he’s left over the middle of the plate and in the strike zone. Opponents missed on 21.1% of pitches he threw there in April and just 12.2% in May.

He left 24.7% of his pitches over the middle third of the plate and opposing batters hit just .189 against pitches there in April. In May, however, he's left a similar percentage of pitches in the middle third of the plate (24.0%), but opposing hitters are batting .407 against pitches in that zone."

Jered Weaver

Pitches over middle third of the plate

April May MLB season avg

Opp BA .190 .407 .301

Opp SLG .286 .741 .497

IZ Miss Pct 23.3 14.3 13.7