Pebble Hunting: A Closer Look at Relievers and Leverage

On April 29, Bud Black summoned Dale Thayer from the bullpen to pitch the bottom of the eighth inning against the Giants. The Padres trailed by three runs and were already 98 percent likely to lose. It was, for Thayer and the Padres and the Giants and Bud Black, a very low-leverage situation. Just three times in his big-league career had Thayer pitched in even an average leverage situation. Every other time, it has been something more like mop-up work. Thayer threw a bunch of strikes and had a perfect inning.

Now skip ahead to September, and here are the situations in which Thayer has been called on:

• Eighth inning, ahead one;
• Seventh inning, tied;
• Eighth inning, ahead one;
• Eighth inning, ahead two;
• Seventh inning, tying run up;
• Eighth inning, ahead one;
• Eighth inning, ahead one;
• Eighth inning, ahead one;
• Seventh inning, down four;
• Seventh inning, tying run on base.

Thayer has roughly the 20th-highest average leverage index* among relievers this month, after having the third-lowest leverage index among relievers in April. His life has changed a great deal in four months. He is like the kid in The Wizard, who had been playing games but nobody cared, and then after a long journey across the country with Jenny Lewis he was playing games and people cared. Don’t rewatch The Wizard, everybody. It’s way worse than you remember.

Bullpens evolve throughout the season, and things like Thayer happen. Here are other things like Thayer that have happened. More specifically, here are the four relievers who pitched a bunch in April and pitched a bunch in September whose average leverage changed the most.

Sam LeCure: .52 average leverage index in April; 2.10 in September
What we said before the year:

He can be spotted in the rotation or handle multi-inning relief chores. If there were ever an "11th man Olympics," LeCure would be on the short list of favorites to medal, and as long as you don't insist he graduate from the role, you're in great shape.

90th-percentile PECOTA projection: 3.91 ERA, 0.4 WARP

Actual stats: 3.13 ERA, 1.0 WARP

What happened: If I told you LeCure has been particularly good this year in high-leverage situations, and that Sean Marshall has been particularly less good, you’d probably be right to brush it aside as a small-sample thing. We’re talking about relatively small differences, over the course of just 50 or 100 plate appearances. You’d ignore it. I’d ignore it. But managers have to sit right next to the guy who stinks of failure, and managers have a hard time ignoring even an unfair stink. So Marshall, one of the best relievers in baseball over the past three years, has been increasingly limited to lefty-on-lefty work this year, working less than in inning in two-thirds of his appearances since July 1. That has opened up the eighth inning, and LeCure—with a 2.52 ERA since late April, and with the best high-leverage stats in Cincinnati’s bullpen this year—has earned a share of those eighth innings.

Turning point: LeCure started getting more important assignments in mid-May, after striking out seven batters (and walking none) over back-to-back outings. But the really high-leverage appearances began this month, when Aroldis Chapman was given extra rest and Jonathan Broxton moved temporarily into the closer’s role.

Steve Cishek: .95 aLI in April; 2.50 in September
Ryan Webb: .49 aLI in April; 2.10 in September
What we said before the year:

(Cishek) has better stuff than his competitors for late-inning work out of the Marlins bullpen, … and his effectiveness against batters of both handedness makes him a sleeper candidate for the occasional save opportunity.

And,

Though (Webb) went 0-for-4 in save chances last year, his ability to limit hard contact makes him a dark horse candidate for stray saves when Heath Bell is unavailable.

90th-percentile PECOTA projection: 3.45 ERA, 0.9 WARP for Cishek; 4.00 ERA, 0.3 WARP for Webb.

Actual: 2.87 ERA, 0.6 WARP for Cishek; 4.24 ERA, 0.6 WARP for Webb.

What happened: First Heath Bell was signed, then Heath Bell was garbage. Both Cishek and Webb, after pitching in low-leverage situations for most of last season, saw their importance spike in September 2011. In a typical Miami offseason, the Marlins might have seen the pair as low-budget late-inning options and handed the ninth inning to Cishek, Webb, or Edward Mujica. Instead, Miami signed Bell, and Cishek and Webb began the year in the second tier of a crowded bullpen.

Cishek was effective in April and quickly passed Mujica on the bullpen hierarchy, then took over the closer’s role after Bell’s sixth blown save before the All-Star break. Webb’s leverage went up after Mujica was traded and has spiked this month.

Turning points: In the first week of July, while Bell was collapsing, Cishek appeared in eight consecutive average-or-higher leverage situations. He struck out nine, walked nobody, and didn’t allow a run, putting him in line to take Bell’s job. Webb had the best stretch of his season in the month after Mujica was traded, including a nine-game period without allowing a walk or an earned run.

But, really, Cishek and Webb don't quite fit what I had hoped this exercise would show. Neither has vastly outperformed expectations. Neither has probably permanently adjusted anybody's expectations. And neither pitcher's chart shows all that much, beyond a slow and not-steady climb up the Marlins' bullpen chart:  

Alfredo Aceves: April 2.55 aLI; September 0.54

What we said before the year:

Such pitchers (as Aceves), though only slightly less successful than their more experienced counterparts, appear far more vulnerable to being bumped out of the closing role for whatever reason … so it shouldn't surprise us if their managers backtrack on their unconventional decisions in relatively short order.

10th-percentile PECOTA projection: 4.45 ERA, 0.3 WARP

Actual: 5.31 ERA, 0.1 WARP

What happened: Aceves didn’t just start out as the Red Sox’ closer; he managed to make it until the end of August, despite the worst ERA by an AL closer (minimum 10 saves) this year. Bobby Valentine’s patience with Aceves makes more sense than that, though; after two terrible outings in April sent Aceves’ ERA up to 24.00, he spent the next four months pitching well, with a 2.91 ERA and three strikeouts per walk. The remnants of that 24.00 never disappeared entirely, though, and two blown saves in late August turned out to be perfect timing for Andrew Bailey’s return. Aceves hasn’t pitched in a Red Sox win since.

Turning point: He allowed three runs to blow a save in the ninth against the Angels. Sent back out for the 10th, he allowed another two. Bailey earned his first save of the season the next day.

Other significant aLI shifts:
Ernie Frieri: .47 in April; 1.70 in September
Koji Uehara: .16 in April; 1.35 in September
Josh Kinney: Didn't pitch in April; 2.05 in September

All aLI's from Baseball-Reference.