Arrieta's stuff is by far the hardest to handle on the staff, and Montero has done the best job of receiving that stuff. I haven't checked recently, but IIRC every strong outing Jake has had in the 2nd half has been with Montero catching. It's not a guarantee, Jake still has the most influence, but Montero is going to do a much better job of stealing strikes and knowing his stuff best for how to attack hitters. As far as the running game goes, that's definitely something to keep an eye on, but I don't think it's reason to avoid Montero's game calling benefits. Here's Arrieta's recent starts: NLCS/Montero: Reddick stole 2nd and 3rd NLDS/Montero: No attempts Pittsburgh/Montero: No attempts St. Louis/Montero: No attempts, Montero picked Adams off Milwaukee/Contreras: Villar steals 2nd twice Houston/Ross: No attempts San Fran/Contreras: Crawford stole 2nd and 3rd Pittsburgh/Contreras: 2 of 3 SB successful San Diego/Contreras: Jankowski steals 3rd Milwaukee/Contreras: Perez steals 2nd Not only does there not seem to be a huge uptick in attempts, but Contreras doesn't seem to have much of an impact either way. Thank you for doing the dirty work on this. This is where I started looking through Montero starts vs Arrieta starts to find the overlaps, and to be honest you're probably right, outside of an August 23rd outing where Jake went 8 scoreless against San Diego with Willson catching. The issue is that that was his last 'good-Jake' start besides his shutdown outing against the Cardinals, which I think everyone remembers. Other than that he's been pretty ordinary, if not below average. I think he can pitch that way to Contreras or Montero, so I don't see the need to cater to him. And I also think Coghlan (or Soler, or Heyward/Almora) is much better in the outfield than Contreras, and that's worth something too. Edit: Fixed which outfielder/catcher I was talking about in the last line.