Yesterday, Alex Cobb was dominant, tossing four innings allowing just 1 hit and striking out 5 while walking not a single batter. It was great to see Cobb pitching well, and he projects to be a big part of the Rays’ rotation in 2013. But the most interesting part of the outing was that for the first time, Cobb broke out a cutter against left-handed batters. Cobb told Marc Topkin that he was really excited about the pitch, picturing as a “strikeout pitch” he could backdoor on the outside corner versus lefties if he can get it working well consistently. Joe Maddon, meanwhile, was hesitant to endorse Cobb throwing the pitch, saying that ”The threat there is always that it can subtract from something else you do well.” With Cobb thinking one thing and Joe Maddon appearing to be against it, it’s certainly up in the air whether Cobb will indeed insert the cutter as a regular pitch in his repertoire against lefty batters. The key question is going to be this: would adding a cutter truly make Cobb more effective against lefties?
In 2012, Alex Cobb was noticeably better against right-handed batters, holding them to a .252/.297/.336 line (81 sOPS+) with a 43-11 strikeout to walk ratio in 247 plate appearances compared to a .256/.331/.404 line (97 sOPS+) with just a 65-29 K-BB ratio in 322 PA’s by lefties. Cobb allowed 11 home runs on the season and 8 were by lefties batters. That certainly makes sense as Cobb is a right-handed pitcher and Cobb wasn’t that bad against opposite-side batters anyway, actually being a bit above-average. Nevertheless, though, Cobb could certainly use improvement against them, and in theory, adding a pitch like a cutter could be a good idea for him. But results are one thing and Cobb’s actual pitches are another. Let’s look at how Cobb’s repertoire has compared against righties and lefties since he broke into the major leagues using the Pitch F/X data from Brooks Baseball.
Looking at these two charts, they’re very similar at first glance, with the main difference being that Cobb used his four-seam fastball as his primary fastball to righties while utilizing primarily his sinker versus lefties. Cobb’s split-change and his curveball were almost exactly the same across the board against lefties and righties as he threw them just about the same percentage of the time with just about the same amount being strikes and the only difference was that he got a more swings-and-misses against lefties and more groundballs versus righties, so essentially those two pitches were just as good versus batters of both sides, maybe a little better to righties because of just how many more groundballs he forced. But the alarming thing for Cobb was that his fastball control and command was not nearly as good to left-handed batters. He threw his fastballs exactly the same percentage of the time (a combined 47%) while generating almost exactly the same whiff rate (4.2% to lefties and 3.7% to righties), but he threw much fewer strikes to lefties (58% versus 65%) and generated several fewer groundballs (1.56 GB/FB compared to 1.76). That was especially alarming because he also got fewer groundballs with his secondary pitches. Against right-handed batters, Cobb forced a ridiculous groundball rate, didn’t walk anyone, and got a fair amount of strikeouts primarily with his outstanding split-change. Against lefties, however, he missed more bats but he walked more batters and allowed more contact in the air, playing more like a power pitcher, which he decidedly isn’t. If he’s ever going to rectify that problems, Cobb has to improve against lefties and fast.
Cobb is a pitcher who will always be extremely depending on his split-change to get whiffs- despite throwing the pitch just 35% of the time, 64.7% of Cobb’s swings-and-misses have been on his split-change. With that in mind, a key for Cobb will be to find a “strikeout pitch” like he referenced to keep hitters off-balance even as they adjust to his split-change. But while that would be nice, the bigger deal for Cobb will be to find a way to force more weak contact against lefties and get his groundball rate against them more in line with what it is against righties. But if used correctly, a cutter could help Cobb do both.
With a cutter attacking the outside corner of the plate, Cobb could force weak contact along with some swings-and-misses thanks to its contrast with his fastball and sinker and in turn, make his fastball and sinker more effective. Most importantly, though, if Cobb added a cutter it could allow him to use his split-change and curveball less, which should make them better as well. Cobb’s cutter is not immediately going to be a pitch that he’s going to be able to control very well, and there’s still the danger of Cobb walking too many batters for his own good versus lefties, especially if he throws it too often. If he throws it 8 to 10% of the time to lefties and maybe 5% of the time to keep righties off-balance, that could be the perfect range for it to not just emerge as a solid pitch for Cobb but make his entire repertoire better.
Alex Cobb’s newfound cutter is never going to be a go-to pitch for him, and if he begins to throw it too often, the adverse effects will outweigh the benefits, like Joe Maddon referenced. However, if Cobb can gradually incorporate it into his arsenal and use it as a change-of-pace from his fastball and sinker and nothing more, it could quickly make him a better pitcher with all of his other pitches benefiting as a result. Before any of this happens, Cobb has to become more comfortable going to his cutter and locate it as good as he will have to in order to be successful. But once Cobb accomplishes that, his will fit perfectly in his arsenal and get him ready for an even stronger season in 2013 as the 4th starter in a Rays rotation that is looking scarier by the minute.