xStats Buy Low/Sell High

Between barrels and launch angle (LA) and exit velocity (EV) and sweet spot (SS) and hard hit (HH) there are a million Statcast numbers out there you can use to make judgement calls on players. And while something can get lost when you try to boil everything down to one number, for me, the simplest way to look at these stats in their entirety is to use x stats and, specifically xwOBA. Comparing a player’s wOBA to his xwOBA can give you a good sense of whether that player has “earned” his results and can help you find guys to buy low or sell high.

We’re not quite to the point where EV and LA (and the xStats based on them) stabilize, but we are far enough into the season (and close enough to trade deadlines) that we need to start making some calls or it will be too late. Consider that your warning/caveat – I am jumping the gun and drawing conclusions I really shouldn’t draw just yet.

But I am going to draw them anyway.

By sorting a Statcast leaderboard by the difference between wOBA and xwOBA we can quickly pull up a few names who stand out as having hit the ball much better (or worse) than their surface stats suggest.

Buy Low

Evan Longoria – I am going to layer caveats on caveats here: San Francisco has three of top five players in terms of xwOBA outpacing wOBA. Hunter Pence is first, Pablo Sandoval second, and Longoria fifth. This might suggest something weird with the SF Statcast data, but for now, let’s assume it is all good. Pence and Panda don’t make this list because even their xwOBA’s aren’t good enough to get excited about, but Longoria, posting a putrid .274 wOBA has a shiny .392 xwOBA. Longoria has posted a career low K% (14.3%) so far this year, and K% stabilizes around 60 PA (he is at 63). This is primarily driven by a low chase rate – he swung at pitches outside the zone around a quarter of the time until 2013, then closer to a third or more through last year. Now he is back to 25.7%. The change in approach comes with similar results when he makes contact – his EV and LA are similar to his past numbers. His xwOBACON (xwOBA on contact) is up (.441) from last year (.429) but not a ton. He does have a much higher barrel rate (12% vs. 7.5% last year), perhaps because he is making contact on pitches in the zone that he can drive instead of ones out of the zone that he cannot. Given he hasn’t been a useful fantasy player since 2016, I am watching rather than immediately buying Longoria. But if those xstats stay high, the K-rate stays low, and he stays a FA, I’ll look to buy if I need help.

Colin Moran – I already wrote about Moran around these parts, but here is more evidence that he is doing something different. His .340 wOBA isn’t any great shakes, though it is solidly above average (particularly for a guy who is MI eligible in ottoneu and some other formats), and his xwOBA (.425) suggests he’s been even better than he looks. He’s going about things in a very different way than Longoria though. While Longo appears to be more selective while making the same contact, Moran is getting more aggressive – he’s chasing more, his swinging strike rate is up, and his K% through 68 PA would represent a career high. But when he makes contact, it is LOUD. His xwOBACON is .578. He’s barreling more than 18% of the balls he hits. His EV is up. And he is doing it by absolutely punishing everything except fastballs. His xwOBA against fastballs in 2019 was .353; it’s .352 this year. Breaking balls were .282 last year and .544 this year. Off-speed was .290, now .481. How sustainable is this? I don’t know, but I have been aggressively buying and will continue to do so.

Sell High

Paul Goldschmidt – Goldy is a guy I have been looking at quite a bit, given the Cardinals large number of remaining games and his potential to help gain ground if you are behind the pace in games played at 1B, Util or (if your league uses it) CI. But his .391 wOBA isn’t supported by a .313 xwOBA. Because the Cards have played so few games, this is based on a smaller sample than others, but it’s still concerning. Goldschmidt has made a career of hitting the ball hard and it shows in his statcast profile – dating back to 2015, he has posted EV’s between 90.1 and 92.2 (though on a downward decline through those years), HH% between 42.4% and 47.2% (also on a decline), barrel rates between 7.8% and 13.6%. This year, those three numbers are 84.1, 30.4%, and 4.3%. This is not your father’s Paul Goldschmidt (assuming the Arizona Diamondbacks are your father). I am not going to be buying Goldy and, if I had him on any rosters, I would be looking to move him.

Rio Ruiz – Ruiz has been a revelation for the somehow-playoff-bound Orioles, but has been a bit hidden on a team where breakouts are all over the diamond – Anthony Santander, Pedro Severino, Renato Nunez, Hanser Alberto are all revelations, as well. Ruiz, however, might be just smoke and mirrors. He is posting a .366 wOBA but just a .291 xwOBA, meaning that if his actual stats start to look like his xstats, you’ll be cutting him pretty quickly. Put bluntly, Ruiz is still Ruiz, but now with more Ks! His HR/FB rate has jumped from 12.5% last year to 37.5% this year, made more valuable by an increase from 34% to 41% in his FB rate. He posted a .294 BABIP last year and is at .372 this year. Presumably, he is killing the ball, right? Well, his EV is down from 88.4 to 87.2. His HH% is down 36.5% to 35%. He has barreled the ball 5 times (12.5%) after totaling just 8 barrels all of last year (2.8%), but it is hard to see that continuing if he doesn’t hit the ball harder more often. He does seem to have improved his average launch angle, hence the increased FB rate, but FB that aren’t hit hard enough do not typically lead to gaudy HR numbers or high BABIP. If you can flip Ruiz for someone, now is the time to do it.


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