The most interesting thing about any trade that will be made in the next few days isn't just seeing a familiar face in a new place, it's about what potential impact a new home could have, especially on pitchers.
Think about it: Sometimes, you have a 2017 Justin Verlander turning his pre-trade 3.82 ERA with Detroit into a post-trade 1.06 mark for Houston, plus a 2.21 ERA in 36 2/3 postseason innings. (See also: 2008 CC Sabathia, among others.) And in the other direction, sometimes you have 2016 Drew Pomeranz, who had a 2.47 ERA with the Padres before being dealt to Boston, where he then posted a 4.59 mark.
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There are an endless number of possible reasons for those changes, obviously, from a new ballpark to a new coaching staff to better or worse defense behind them to a first half that may have been out of the ordinary for the player in the first place to simple random variation, another way of saying "these things happen." But the point is, sometimes you can see some signs of life in pitchers who may be better off trying something new somewhere new. These four, perhaps, might fit the bill.
Dylan Bundy, Orioles
Bundy's career hasn't at all gone the way Baltimore might have expected when they made him the No. 4 overall pick in the 2011 Draft, just ahead of names like Anthony Rendon, Francisco Lindor, Javier Báez, and George Springer. After somewhat shockingly getting a brief cameo at age 19 in 2012, Bundy didn't return to Baltimore again until 2016 thanks to Tommy John surgery and a shoulder injury. While he's generally been healthy over the last few seasons, his career 4.72 ERA isn't particularly impressive, nor is the fact that it's an ugly 5.34 since the start of 2018.
So what's the appeal here? It's in the underlying metrics. In terms of hard-hit rate, strikeouts (102 in 98 innings) and walks, Bundy has pitched roughly like a league-average starter this season. (By Statcast quality of contact metrics, he's been something along the lines of Joe Musgrove or Andrew Heaney.) Only four regular starters have under-performed their expected outcomes by as much as Bundy has.
Bundy's expected wOBA: .311
Bundy's actual wOBA: .345
MLB SP wOBA: .320
That's not star-level, obviously, but it's useful, and it's not hard to see why the ERA might be inflated. The rebuilding Orioles have perhaps baseball's weakest defense and weakest bullpen, plus they play in a hitter-friendly home park; over the last two seasons, he's allowed a .532 slugging at home and a .487 on the road.
Again: There's not likely the star we once expected buried in here, not with a fastball averaging 91 mph. But Bundy is still just 26, he's got 88th percentile spin on his fastball, he's got a slider that's been one of the 12 most effective from starters this year and he's got tons of reasons to suggest that a change of scenery might provide improved results. Bundy pitched effectively in his return from a minor knee issue on Tuesday night; might it have been his final start as an Oriole?
Ian Kennedy, Royals
You might not think that Kennedy needs help looking better, because after a few seasons unimpressive enough as a starter that it landed him in the bullpen this year, he's been a revelation as Kansas City's unexpected closer. Last year, he struck out a below-average 20.3% of hitters; this year, he's striking out an above-average 28.6%. At the same time, he's posting career lows in walk rate and home run rate, almost certainly related to a velocity increase from 91.9 mph to 94.1 mph.
That said, his ERA of 3.48 is more "good" than "great," which is interesting given that all of the strikeouts and lack of walks and hard contact have him pitching like he's one of the 15 or 20 best relievers in the game. (Put another way, he's striking out more and allowing fewer walks and homers than Shane Greene ... who has a 1.22 ERA.)
One potential reason why: Based on the exit velocity and launch angle he's induced (or lack of it, as he's got a career high 45% ground-ball rate), Kennedy's expected batting average on balls in play is .284, well below the Major League average of .312. But his actual BABIP is .376, and the resulting gap there is the largest in baseball. Maybe it's simple bad luck, or the weak infield defense at first and third (though up the middle has been strong).
It's not guaranteed to change, because that's now how these things work, but it's hard not to notice that he's perhaps "earned" better outcomes than the good one he's already received. If even a few of those bouncers turned into outs, Kennedy's strong numbers look even better.
Noah Syndergaard, Mets
The Mets probably won't trade Syndergaard because his 4.36 ERA might make it something of a "selling low" situation, but if they did, he might benefit in getting away from the poorly regarded Mets defense. That's especially true on the infield, where 28 of the other 29 teams have added -- or "not subtracted as much," if you prefer -- more value on grounders than the Mets have.
That being the case, you might expect to see some Mets pitchers suffering due to this ... and Syndergaard has, more than any other. He's allowed a .277 average on ground balls, and that's 50 points higher than the .227 you might have expected based on the quality of contact he's induced. Only three pitchers have been hurt more. That's a big deal, because based on the quality of contact and amount of contact Syndergaard has allowed, he's been a top 10 starter over the last two years, even if the results clearly don't reflect that.
So it seems reasonably safe to assume that placing a better defense behind Syndergaard might help, but it might even go deeper than that, because it seems he's rarely been able to get the most out of his prodigious talent. Syndergaard's most-thrown pitch this year? His sinker, at 30.4%. The pitch getting hit hardest this year? His sinker, by a lot, with a .506 slugging percentage. The pitch missing the fewest bats this year? His sinker, with a 16.3% strikeout rate.
It's not that the Mets don't know all that, obviously. But one can easily imagine what a team like the Astros might be able to do here.
Aaron Sanchez, Blue Jays
Sanchez, it probably goes without saying, has had a rough few years. He's got a 6.06 ERA. In 50 starts since his breakout 2016, he's got a 5.30 ERA. It hasn't been great, and there's no way to suggest this is about bad luck or bad defense -- it's been bad performance, though there was a glimmer of hope on Tuesday when he allowed just a single run (and more importantly, zero walks, for the first time in 60 outings)
No, this one is about curveballs, or, perhaps more accurately, the lack of them. Sanchez, at his best, thrived on his sinking two-seamer, which he regularly threw 55-60% of the time. Thing is, that's not how baseball works anymore. Sanchez's sinker is getting lit up (.375 average, .570 slugging). His four-seamer is getting lit up (.282 average, .518 slugging).
But the curveball ... the curveball might be the difference-maker. Sanchez gets swing-and-misses on just over 36% of swings on his curve, better than the league average of 31.5%. Batters have a .198 average and a .307 slugging against it; it's got 95th percentile spin. It gets 50% more break and 8% more drop than other curveballs at his velocity and release, and when he throws it right, it does this:
Sanchez, to his credit, is throwing it a career-high 22% of the time, but that's also three-quarters of the time where he's not throwing it. In the new world of baseball, where "take your best pitch and throw it a lot" is a perfectly acceptable approach, dropping one of those fastballs and throwing the curveball even more might be just what Sanchez needs. Maybe that requires a move to the bullpen. Maybe that requires a move out of Toronto. It might not work. But it's worth the risk.
Mike Petriello is an analyst for MLB.com and the host of the Ballpark Dimensions podcast.