The very Minnesotan outfielder has a legitimate cannon attached to his right shoulder, yet baserunners attempt to take extra bases against him at the third-highest rate advance attempt rate of all outfielders. One diminutive teammate, meanwhile, had the second-weakest arm at the position in , yet tied for the lowest advance attempt rate.
Make it make sense! It would be natural to assume a strong correlation between the strength of an outfielder's arm and the advance attempt rate against that defender. That is to say, we might assume that the stronger the outfield arm, the more conservative baserunners will be. However, while that might prove mostly true, Matt Wallner and Manuel Margot are counterexamples, reminding us that there is more to throwing runners out than having a Howitzer.
As Wallner looks to be the heir apparent to Max Kepler in right field, I felt it would be worthwhile to look at what might be the reason for this discrepancy.
Naturally, my first thought was to consider the accuracy of his throws. Arm Accuracy This isn't quantified publicly yet , so I put on my amateur scouting goggles, watched a few dozen plays, and found nine where Wallner was attempting to throw out an advancing base runner.
Of those nine, I determined that six of those were inaccurate throws. That's not to say that the runner would have been out had the throw been better, but it is to say that Wallner made a legitimate attempt to throw out a runner and the throw was off-line. Maybe I was too harsh, but even if the throw was simply on the wrong side of the bag like this one , I deemed it inaccurate.
