About ten years ago, baseball started to undergo a statistical revolution: youth became valued, OPS was born, and walks finally became valued. Fast forward a decade and OPS is now a mainstream stat, multiple sites are constructing competing ways to summarize the total value of a player, and even in baseball clubhouses sabermetrics are the new cool kid on the block.
But there are still a few areas of baseball strategy stuck in the dark ages of gut instincts and wild speculation, and chief among them is use of pitchers.
Right now it baseball there are three types of pitchers: starters, relievers, and closers. Starters come in to pitch the start of the game, stay in for at least five innings, and are eventually taken out. They pitch every five days. Closers come in in the ninth inning with a lead of between one and three runs. They never pitch more than an inning, and never come in otherwise. Middle relievers pitch in between starters and closers.
These roles bear an uncanny resemblance to two of the stupidest pitching statistics, wins and saves.
This system is, of course, not close to optimal. Frequent pitching changes at the beginning of the game would allow a manager to get better matchups, keep pitchers fresher from stopping them from having to throw too many pitches in one day, and allow pitchers to throw however many pitches is best for them--not a bimodal distribution with centers at fifteen and one hundred.
It would also give an NL team another advantage--they could always pinch hit for their pitchers (or at least as long as it wasn't a two out, none on situation).
I'll look at the first effects in a later post, but for now, how much would always pinch hitting help?
Well, first I found the number of runs scored by an average NL lineup from 2011 using Basim; it was 3.799.
Then, I substituted the average substitute player for the league in for the ninth spot in the lineup; Basim then simulated it and found an average of 4.006 runs per game.
That's roughly a 3.2 win difference right there--the difference between a .500 team and a .520 team.
It's true, of course, that implementing such a system could incite a revolt from pitchers--but it seems like there is too much to be gained for it to be worth ignoring as a manager.