Game 96, Mariners at Astros – Paxton’s Situational Splits

marc w · July 19, 2017 at 11:26 am · Filed Under Mariners 

James Paxton vs. Charlie Morton, 11:10pm

It’s an early one today for getaway day in a pretty important series. Tied at a game apiece, the M’s could get an important psychological and playoff-odds boost by beating the Astros in Houston, and the M’s are handing the ball to their ace, James Paxton.

It’s been another very good season for Paxton, full of the full spectrum of Paxtonian features we’re so familiar with. He’s remarkably difficult to hit, with a H/9 ratio that would rank in the top 10 in the AL if he qualified (he’d be nearly tied with teammate Ariel Miranda, actually). His easy velocity and deathly curveball allow him to rack up strikeouts at obscene rates, even by the K-saturated 2017 standards – again, if he qualified, his K/9 would rank in the top 5 in the AL. On the down side, he’s already spent some time on the DL, which seems almost inevitable at this point, and he’s also got an ERA far higher than his FIP. That last one’s kind of odd, as we often expect pitchers with tons of velocity and bat-missing stuff to post higher strand rates – it’s a lot easier to get out of a jam when you can just strike out a few batters in a row, after all. Paxton’s BABIP’s a lot more normal this year than last, so it’s not that he’s getting BABIP’d to death. Instead, it looks more like a case of struggles with men on base.

It’s easy to chalk that up to random noise. After all, he had a lower ERA than FIP back in 2015 *and* 2014. Of course, Paxton changed everything between 2015 and 2016, so maybe he’s doing something different now. To check, I looked up some statcast numbers to see if I could see why his wOBA is nearly 100 points higher with men on base than with the bases empty this year, and why he’s shown huge splits in this measure 2 years running. For some context, let’s take a look at the league as a whole. The league’s wOBA-against with no one on this year is .323, and with runners on base, it rises to .331. This rise is despite a *drop* in exit velocity on contact from 87 to 86 MPH (though expected wOBA does rise slightly). This makes some sense, as a 1B holding a runner on can provide more holes for ground balls to reach the outfield. Finally, there’s zero difference in the pitch height that pitchers throw or that batters hit with men on vs. not – the league average pitch height is 2.33 feet regardless.

Paxton looks quite different, though. With no one on, his expected WOBA is a dominant .220, which rises to .300 with men on. That huge wOBA spread isn’t purely luck, then; he’s been somewhat unlucky, but the real story is that he’s giving up much different contact in these different situations. The bulk of THAT comes from a huge 3+ MPH jump in the average exit velocity he’s giving up with men on base. Remember, the league as a whole showed *lower* exit velocities with men on. Moreover, his average pitch height changes, dropping about 0.2 feet with men on base. So he’s just throwing it lower, and that’s his problem? No, not exactly. Overall, he’s at his best when he IS throwing low. His wOBA-against is about 100 points lower when the ball crosses the plate 2 feet high or lower – the bottom half of the zone and below. While he’s still got those weird splits with men on base, he’s *still* limiting damage on low pitches (unlike the league, which is hitting more and more HRs off of low pitches). Oddly, it’s not that batters wait for an elevated fastball, either – they hit better on balls near the top of the zone and above, but it’s nothing dramatic. What *is* dramatic is what happens on pitches right in the heart of the zone. With no one on, Paxton gets away with these pitches (.230 wOBA this year, .310 over 2016+2017 combined). With men on, for some reason, he doesn’t (.525 wOBA this year, .423 combined).

Paxton throws more non-fastballs with men on, as many pitchers do. It’s not extreme by any stretch, but he’ll throw more curves and cutters. Batters aren’t hitting those pitches, however – he’s got a tremendous wOBA-allowed on breaking stuff in all situations. This is strictly a fastball problem. Despite throwing more breaking stuff with men on, batters have put a higher percentage of balls in play off of Paxton’s fastball than they have with no one on…when he throws fewer fastballs. This seems like a situation where batters focus in on a very small part of the zone and look for a specific pitch in that zone. When they see it, they swing like hell at it. So what can Paxton do? Well, he might want to throw more breaking balls in these situations. Tom Verducci has a great article at SI today about the Yankees throwing the fewest fastballs despite having a pitching staff with super high average fastball velocity. I’ve mentioned this philosophy a lot this year, as this is essentially the Astros’ game plan, too. Paxton’s got a great fastball, and I don’t think he should adopt a full-on Astros/Yanks-style pitch mix. Rather, in order to have fewer grooved fastballs in situations where grooved fastballs can hurt him most, he should throw fewer of them, and perhaps use them a bit differently.

All of this is small-sample stuff, which is kind of obvious given Paxton’s injury history. I haven’t proven anything definitively. But I hope the M’s aren’t just banking on some regression and not worrying about these splits. Paxton’s been great, and that’s a huge help to the M’s. He doesn’t have to throw many pitches with men on base thanks to the aforementioned greatness and his success at limiting hits. That there’s still some room between his unbelievable talent and his actual runs-allowed is kind of encouraging. Over the past two seasons, Ariel Miranda, acquired for Wade Miley and never a big prospect, has allowed an RA9 of 4.24 in 165 2/3 IP for the M’s. James Paxton, 98 MPH-throwing, curveball wizard, staff ace, has allowed a 4.10 RA9 in that time period, in 208 1/3 IP. In this day and age, that’s pretty good, but if his RA9 was close to his FIP across 2016-17, he’d have allowed *30* fewer runs. That’s…that’s a lot. Throw out all the unearned runs he’s allowed, and if you pulled his ERA down to where his FIP’s been, he’d have allowed around 20 fewer runs in roughly a full season’s worth of innings. As a marginal playoff hopeful, these marginal improvements matter.

1: Segura, SS
2: Gamel, RF
3: Cano, 2B
4: Cruz, DH
5: Seager, 3B
6: Valencia, 1B
7: Dyson, CF
8: Zunino, C
9: Heredia, LF
SP: Paxton


5 Responses to “Game 96, Mariners at Astros – Paxton’s Situational Splits”

  1. mksh21 on July 19th, 2017 4:12 pm

    Cano is having his worst stretch of the year and we are still kicking ass… We MIGHT not be terrible.

  2. Notfromboise on July 19th, 2017 4:17 pm

    This is the best hitting team we’ve had in over a decade. Considering we’ve gotten almost nothing out of the pitching staff the entire season, it’s amazing and exciting to be .500.

    Amazing because Kuma and Smyly didnt factor into the season at all.

    Exciting because between Mirada, Moore, Paxton, and Felix we kinda sorta almost have ourselves a pitching staff now. Which makes the kind of run we will need to go on in the next couple months possible. Very exciting.

  3. Longgeorge1 on July 19th, 2017 6:16 pm

    If the injuries can get left behind this team can win. For various reasons I have not been posting here much but my interest in the M’s is as high as it gas been in years.

  4. Grayfox3d on July 20th, 2017 1:43 am

    If our 3-4-5 hitters could just show some more consistency as a group, we would be really dangerous. Now to work on this starting pitching unit.

  5. heyoka on July 20th, 2017 7:41 am

    Do these M’s have….SoDo Mojo?

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