David Ross Is Jon Lester's Secret Weapon

Lester has been really lucky this season, but Ross has helped him strand runners.

Early in the baseball season, there are plenty of pitchers who have misleading traditional statistics. A few bad bounces here and there could completely change a pitcher’s earned run average through five or six starts.

One factor that indicates how lucky a pitcher has been is left-on-base percentage (strand rate). While some pitchers have qualities that make them more likely to strand runners, it’s unlikely that, over the course of a season, a pitcher will continually allow a lot of baserunners on base and give up few runs.

It’s interesting to note that the two luckiest pitchers in terms of strand rate this season are both Chicago Cubs. Jake Arrieta is second in strand rate, leaving runners stranded 95.9 percent of the time. While it’s likely that comes down, that would also require Arrieta to give up runs, a concept foreign to him.

But not even The Bearded Wonder has a strand rate as high as Jon Lester’s. After yesterday’s start, Lester’s strand rate is up to an insane 96.2 percent. That will obviously come down, as Zack Greinke led the league last year with a strand rate of 86.5.

Getting out of Jams

In his last two starts, Lester has loaded the bases with nobody out, and he didn’t allow a run in either of those innings. He made some great pitches to get out of these jams, but it’s unlikely he’ll continue to emerge unscathed in these situations.

Lester’s strikeout rate helps get him out of jams, as he’s 24th in the league in that department at 24.7 percent. There have been several times this year that a ball in play would’ve likely brought in a run against Lester, but he’s been able to get a strikeout instead. But Lester’s strikeout rate last season was 25.0 percent, and he still only had a strand rate of 71.8 percent.

There is a secret weapon that has helped Lester keep his strand rate high, and that is his 39-year-old catcher, David Ross.

How Ross Has Helped

Ross’ ability to control the running game has been a huge boon to Lester.

Ross has looked better physically this year and has lowered the percentage of successful stolen bases against him. Last season, base stealers converted at 74.2 percent of the time against Ross, and this season that is down to 68.8 percent.

Out of the 30 catchers who have seen at least 10 stolen base attempts against them, Ross is 11th in caught stealing percentage.

Those numbers are even better with Lester on the mound, as only three of five potential base stealers have stolen successfully against the Lester-Ross pairing in six games this year.

It seems like it’d be easy to steal against Lester with his problems throwing to first base, but it hasn’t been. Part of this is Lester's being as quick to home as almost any lefty in the league, which makes it difficult to get a good jump.

If runners can’t steal against Lester, it would seem that they could at least get big leads against him. After all, if he can’t throw to first, it would stand to reason that taking enormous leads would be prudent.

That’s what Pittsburgh Pirates utility man Sean Rodriguez was thinking yesterday in the second inning. And then Ross picked him off from behind the plate.

It’s the second pickoff of the year already for Ross, who led the MLB in pickoffs for catchers last year. And it’s his willingness and ability to throw behind runners that has kept them close to first. After Rodriguez was picked off, Pittsburgh’s runners were very cautious with secondary leads and, as such, couldn’t get great jumps on balls put in play.

A Dynamic Duo

The abilities of Ross to keep runners honest both in terms of steal attempts and big leadoffs could be a contributing factor to Lester’s strand rate. If runners are unable to swipe bags or take big leads, they’re much less likely to score or go from first to third on the next base hit. And if they can’t advance extra bases on the next base hit, Lester has another chance to strand them.

There is a reason that, as a team, the St. Louis Cardinals have had the best strand rate since catcher Yadier Molina entered the league. Molina has been the best catcher at keeping runners honest over the last decade, and the Cardinals have reaped those benefits. While Ross isn’t in the same league as Molina, his performance this year has definitely helped.

So, expect Lester’s strand rate to come down, as it’d be foolish to think he’ll continue to have this much success with men on base. But, if Ross can continue to be in the back of baserunners head, expect that rate to be better than last year.