For the most casual of Mariners fans, the fan who tunes in for a few innings here or there throughout Spring and early Summer but may start to get locked in as they’ve heard that the twenty-year playoff drought is about to be over, the weekend series against the Los Angeles Angels had to be confusing. “OK, so my team has a 98.9% chance of making the playoffs according to Fangraphs” (play along that the super casual fan looks up playoff odds at Fangraphs). “They are playing the easiest schedule in all of baseball for the rest of the season” (continue to suspend disbelief for the super casual fan continuing to browse Fangraphs). “Why does that dude in left field never get to anything hit remotely near him?” (eye test, not Fangraphs). Then they go to Twitter and see that Winker Is trending in Washington. “OH, that’s that guy playing left field for the Mariners. I wonder what that’s about?” The answer to that question would be dozens of loyal, diehard fans lamenting that Jesse Winker is possibly the worst defensive OF in all of baseball.
According to defensive runs saved, a metric that even our hypothetical casual fan perusing Fangraphs may not have thought to check, is the worst defensive OF in all of baseball among qualified hitters (actually, all OF, as most hitters get pulled when they are this bad). Winker has given up 15 runs over the average OF and is three runs worse than Kyle Schwarber of the comically defensively challenged Philadelphia Phillies. What may be even more telling to super casual Seattle Mariners fans tuning in for the Angels series is that Winker started the weekend with -13 DRS. He literally was responsible for 2 of the Angels’ runs and, given the timing, lost the game on Saturday.
But, even the most casual fan might think to look at more than one defensive metric. So, among the publicly facing metrics, one might glance at UZR (ultimate zone rating). Winker fairs better there. He’s only the seventh worse defensive OF behind notable names like Schwarber and Juan Soto. UZR proclaims that Winker has only cost the Mariners 5.5 runs compared to 8.2 at the bottom of the leaderboard held by Anthony Santander of the Baltimore Orioles. The latter plays both RF and LF, while Winker plays LF exclusively.
So, naturally, the curious, casual Mariners fan would want a tie-breaker. UZR/150 seems too close to UZR as it is merely the UZR metric weighted for 150 games, even though Winker is “only” the eighth worst OF by that measure, costing his team 6.2 runs per 150 games, behind six guys casual fan hasn’t heard of and, again, Kyle Schwarber. Indeed there are other websites and other metrics. And you would be correct casual Mariners fan. Welcome to Baseball Savant, the public-facing version of Statcast, which tracks player and ball movement inside the ballpark. All those fun launch angle and exit velocity graphics you see on TV come from Statcast.
For defensive players in the field, there’s a nifty stat called OAA (outs above average). As Statcast charts the movement of players and the result of the play for literally every single play during an MLB season, a baseline can be determined of which balls hit to a specific location, at a particular angle of launch, and at a specific exit velocity should be caught. Using OAA, Winker is right there again in the bottom five of all outfielders with -9, which translates to -9 runs prevented, also third worst among qualified left fielders.
So, the next time you turn on the ROOT Sports broadcast and hear Dave Sims blathering on about how the Mariners are the best defensive team in all of baseball because they have the fewest errors. Ignore him. The team as a whole is excellent defensively, top 10 by advanced metrics. Know that errors are stupid, and you don’t get credited with one if you don’t even get to the ball. And know that the team would be even better in the field if someone else played left besides Jesse Winker.