What is a simulated game? We asked former Blue Jays pitching coach Bruce Walton

After a successful 40-pitch simulated game last week, Marcus Stroman is scheduled to pitch a 55-pitch simulated game today, his last scheduled simulated game before he gets real game action in single-A Lansing next Wednesday.

[Update: In Stroman's own words, he "crushed" his simulated game today.]

The main goal of a rehabbing starting pitcher is to slowly get him stretched out so he can build up his pitch count, generally with the goal of hitting 95–100 by the time he returns to the big leagues. In this case, because there is a short rehab time limit for Stroman, the Blue Jays may have to settle for a lower target. Stretching out Stroman to around 85 pitches, as is planned for his final scheduled rehab start for the Bisons, will give the Blue Jays maximum flexibility. As Alex Anthopoulos often says, it’s easier to put a stretched-out pitcher in the bullpen than to extend a reliever.

Because real game situations present too many uncontrollable variables, teams’ rehab programs often have pitchers throw a few simulated games before progressing to minor league games to build up arm strength and stamina as well as to ensure that he is healthy enough to continue.

Control over the game elements is a huge benefit to playing simulated games. The rehabilitation coach can control not only overall pitch count, but pitch counts per inning, how often and when the pitcher throws from the stretch, and how long to allow him to rest between innings. The coach can decide whether to have the pitcher deliver behind a batting practice "L" or whether to allow him to practice defense. (I'm pretty sure Marcus Stroman will not be asked to practice bunt defense. Ever again.)

But what is a simulated game anyway? We didn’t know, so we asked former Blue Jays pitching coach Bruce Walton.

At one point I had an image in my head of rehabbing pitchers pitching against a screen like in a golf simulator, but they actually throw off of a proper mound on a diamond to a catcher with a batter in the box but with no infielders or outfielders. In most cases, each simulated at bat proceeds like in real game situations, with the batter swinging away and trying to make contact. When the hitter doesn’t make contact, the catcher (or a coach) calls balls and strike. When he does, the same person calls out "out" or "double" or "sac fly" depending on the way the ball was hit. It’s kind of like how my friends and I played when we didn’t gather enough other kids to field.

When no batter manages to get on base in the simulation, the pitching coach may just create, uh, fake simulated baserunners to get the pitchers to pitch in various situations, and work on pickoffs.

A goal is often set out prior to the start of the simulation, for example, in Stroman’s scheduled simulated game today, he may be asked to reach 55 pitches in four innings. In that case, no matter what happens, each inning will end in 13 or 14 pitches. He could have recorded no outs, one out, five outs, or be in the middle of an at bat, when the simulated inning ends. Between each inning, the pitcher is given five to ten minutes to cool down and rest.

The rehab pitching coach will stand behind the catcher pitcher the whole time and will keep an eye on the pitcher’s mechanics and actions before and after every pitch to make his assessment on the pitcher’s progress. If the rehab coach deems it a success, the pitcher is one step closer to returning to the big leagues.

Bruce Walton pitched briefly in the major leagues over four seasons with the Athletics, Expos, and Rockies from 1991 to 1994. After a year in independent ball, the Blue Jays hired him to become a minor league pitching coach and he was promoted to the role of minor league pitching coordinator in 1998. After four-and-a-half years in that role, he became Toronto's bullpen coach from 2002 to 2012 when he was promoted to pitching coach. Afterwards he became the pitching coach for the Iowa Cubs before retiring from professional baseball. He now lives in Calgary, Alberta and coaches amateur baseball players.