Consider this: Through Sunday, we've tracked 1,128 individual catcher throws to second base on steal attempts. Despite starting only 15 games at catcher (he's been the designated hitter a few times so far), Sanchez is tied for the third-strongest throw by anyone this year -- as well as owning three of the top seven, and five of the top 10.
Hardest throws to second base on steal attempt, catchers, 2016
1. 89.3 mph -- Christian Bethancourt, Aug. 22
2. 88.3 mph -- Bethancourt, July 20
3. (tie) 87.8 mph -- Sanchez, Aug. 5 / Sanchez, Aug. 27 / Cameron Rupp, June 2
6. (tie) 87.4 mph -- Sanchez, Aug. 24 / Martin Maldonado, Apr. 14
8. (tie) 87.2 mph -- Sanchez, Aug. 11 / Bethancourt, July 23
10. 87.0 mph -- Sanchez, Aug. 22
MLB average: 79.1 mph
That's impressive company, or at least it ought to be. Remember, Bethancourt's arm is so well-respected that in addition to his catching duties, the Padres have used him both as a pitcher and a corner outfielder this year. Put another way, the 10 throws listed there make up less than the top one percent of the best throws by all catchers this year, and Sanchez alone has half of them in just a few weeks of play. Unsurprisingly, of the 70 catchers with at least five attempts to stop stolen bases at second, Sanchez's average arm strength of 87.4 mph is the best, topping Bethancourt's 86.5 mph and Drew Butera's 84.9 mph.
So far, Sanchez has thrown out six of the nine baserunners who have attempted to steal against him; for comparison, Colorado's Nick Hundley has also thrown out six, but of 53. In an obviously small sample size, that 67 percent success rate is the best of the 82 catchers with at least five total stolen-base attempts against, at all bases.
Interestingly enough, that strong arm helps to mask a roughly average or ever-so-slightly below exchange time, which is to say that part of what makes a catcher successful is how quickly he can get the throw out of his hands after he receives the pitch. Going back to that same list of 70 catchers with five attempts at second base, Sanchez's exchange time of .78 seconds is tied for 54th, slightly below the Major League average this year of .74 seconds. (The best is David Ross, at .64 seconds, and it progresses up in fractions until you get to Devin Mesoraco, who was rarely healthy this year and had a mark of .86 seconds.)
When you combine exchange time and arm strength into "pop time," which measures the time from the pitch being received to the throw being received, which by definition requires a good throw, Sanchez ends up tied with Salvador Perez for sixth at 1.9 seconds, where J.T. Realmuto is the leader at 1.84 seconds and Bethancourt is second at 1.85. There's different ways to get there -- Sanchez and Betancourt have elite arms, Realmuto has an above-average arm plus an above-average exchange time -- but either way, Sanchez has proved himself to be stellar.
Now: Perhaps you've heard us on the Statcast™ Podcast or on social media over recent weeks putting forth an argument that catcher's arm strengths, by themselves, aren't as important as you'd think in terms of preventing stolen bases. We've said that because nearly 70 percent of all our tracked throws to second here fall in a relatively narrow band between 77 mph and 82 mph, and because throw accuracy, pitcher release time, runner speed, and lead distance all seem like they may matter as much or more. We'll be working to prove that in the coming weeks and months, in these pages.
But for every rule, or assumed rule, there's always going to be outliers. In the case of Sanchez, who made his most recent return to the big leagues less than a month ago, we seem to have exactly that. Small samples or not, you can't fake arm strength like this. For all the talk of his hitting feats, clearly he's not going to be hitting .405 for the foreseeable future. The arm, though, that's very real. We expected that coming up. Now, we know it for certain. You can be pretty sure that opposing runners have figured that out, too.