Remember that Josh Tomlin isn’t even really supposed to be here. Not that there’s anything wrong with him, but the Indians like Corey Kluber, and they like Trevor Bauer. They liked Danny Salazar, and they liked Carlos Carrasco. If the Indians had their druthers, Tomlin, perhaps, would be a bullpen long guy right about now. Maybe he would’ve been left off the roster entirely. Not only will Tomlin now start a game that could deliver the Indians a World Series championship — he’s going on short rest. Don’t lose sight of how the Indians are a miracle.

Of course, by name value, the Game 6 starter matchup is frightfully uneven. The Cubs are happy to be going with Jake Arrieta, because a year ago, he was maybe the best pitcher on the planet. Tomlin, meanwhile, recovered from shoulder surgery before making 10 starts. This year, Arrieta took a step back, but Tomlin basically lost his rotation spot. Go off perception, and it feels like the Cubs have a great chance of extending this all to seven. Anyone who knows anything would rather have Arrieta on the mound.

Arrieta, see, is the more talented pitcher. He’s the tougher pitcher to hit. He has higher-quality stuff. The edge Arrieta doesn’t have is in recent results. In what amounts to the most recent history, Tomlin has done a better job of pitching.

I see you over there. I see you preparing to call me an idiot. This is literally Jake Arrieta against literally Josh Tomlin. Arrieta projects for a 3.08 ERA. Tomlin, 4.48. Those are numbers we have on this very website, and it would be irresponsible of me to ignore them. I don’t mean to ignore them. By highlighting them here, I’m not ignoring them. In the longer-term, of course I see Arrieta as the better starter. What’s more relevant, though, is who’s better right now. That’s a lot less clear.

I have for you two tables, informed by FanGraphs and Baseball Savant. The tables compare Arrieta and Tomlin, and the first one shows numbers through early September, when Tomlin temporarily lost his job.

Arrieta & Tomlin Through 9/5 Pitcher IP ERA- FIP- xFIP- Exit Velo Launch Angle Whiff% Strike% Jake Arrieta 174.0 69 83 89 87.3 8.5 10% 63% Josh Tomlin 148.1 114 122 97 88.9 11.4 7% 68%

I think that’s about what you’d expect. Tomlin gets the edge in strikes, and the gap in xFIP- isn’t huge. But Arrieta is tougher to make contact against, and Arrieta demonstrated that he could reduce contact quality, whereas Tomlin for a while resembled a home-run machine. There’s an enormous gap in adjusted ERA. There’s a similarly enormous gap in adjusted FIP. Tomlin got the boot for a reason. And though this Arrieta wasn’t 2015’s Arrieta, this version was fine. A few too many walks.

The second table shows numbers since Tomlin returned to the rotation. The playoffs are included here, and for both pitchers, we’re looking at seven starts.

Arrieta & Tomlin Since 9/6 Pitcher IP ERA- FIP- xFIP- Exit Velo Launch Angle Whiff% Strike% Jake Arrieta 40.0 108 97 95 87.5 13.9 12% 61% Josh Tomlin 41.0 41 65 93 86.0 5.5 8% 68%

Arrieta remains tougher to actually hit, but the difference in strike-throwing has widened. And, over the seven starts, Tomlin’s allowed one home run. In his first 25 starts, he allowed 35. You can see some supporting evidence elsewhere. Relative to earlier, Tomlin’s average exit velocity allowed has dropped by three ticks. And his average launch angle allowed has dropped by a significant six degrees. By exit velocity, Tomlin has jumped from the 57th percentile to the 91st. By launch angle, he’s jumped from the 49th percentile to the 87th (assuming simply that lower is better). Josh Tomlin’s been getting weaker contact and grounders, while Arrieta has had increasing problems consistently finding the strike zone.

It never makes sense to ignore a projection. Again, I do believe that Arrieta remains the superior pitcher. But I think we have Arrieta in a minor relative rut, while Tomlin is on a hot streak. My sense is that pitchers are more able to make changes than hitters, and so projections might apply less often. Arrieta has had issues with his mechanics for some months. His location has suffered as a consequence. And Tomlin has altered his own approach of late, demonstrating another thing pitchers can do to at least temporarily shed their track records. As chronicled by August and Mike Petriello and others, Tomlin these days is featuring a ton of curveballs, which he’s been able to keep down.

Tomlin has also moved away somewhat from his cutter, favoring a two-seamer. Last game, actually, the cutter came roaring back, but the four-seamer nearly disappeared. The bigger, general point: Tomlin has elected to pitch differently, and hitters have hit him differently. I doubt it’s completely a fluke.

Tomlin remains a guy with a small margin of error. That’s something I’m sure he knows about himself. Arrieta gets a little more wiggle room, and for all I know, something will have clicked mechanically between his last start and this one. Even in his last start, he didn’t allow a hit for several innings. Jake Arrieta isn’t some garbage starter, and the Cubs are happy to have him, even when he’s not so precise.

But the way Tomlin’s gone, I’m not convinced this is an awful mismatch. Not in Game 6, and not with Arrieta having to face so many switch-hitters and lefties. Against Tomlin, you can put the bat on the ball, but more of those balls are now headed to the ground. Against Arrieta, contact can be tricky, but you can wait out pitches outside of the zone, and he’s likely to issue his walks. These are two very different starters, and they’re going to pitch with two very different strategies. I’m not sure one is all that much better than the other, simply in terms of this particular game day, so don’t let your brain get ahead of itself.