Substitution Rules

In September of 2013, Billy Hamilton made his MLB debut. As a pinch runner. It’s wonderful to see Billy Hamilton be a pinch runner. A few days before his 20th birthday, Tim Raines made his MLB debut as a pinch runner, and all six games in his September callup was as a pinch runner. He played 15 games the next season, 7 of which was as a pinch runner. (The season after that, 1981, is when he established his star.)

I see nothing but positive about this kind of development. The only reason we see it in September is because of the loosening of the roster rules. Now, rather than expanding the rosters during the season, or declaring a 15- or 20-man roster on a game-by-game basis, what would happen if we changed the substitution rules?

Say you bring in Hamilton to pinch-run for the catcher. At the end of the half-inning, the manager currently has two choices: (a) choose whether to bring in a new catcher and knock Hamilton out of the game or (b) double-switch Hamilton into the game, with a new catcher. In either case, the original catcher is knocked out of the game. But, what if we add a third option: (c) allow the manager to keep the original catcher while knocking Hamilton out of the game. The substitution still knocks one player out of the game, but now the manager gets to decide which of the players involved gets the boot.

And you can extend that to pinch hitting as well. And if you do that, you can also do away with the DH. You can now bring in a pinch hitter for your starting pitcher in the second inning, without knocking out the pitcher (but you do lose the PH): You simply let the PH hit, and then that guy is out of the game, while the pitcher remains. And the same applies for a defensive substitution: at the end of the half-inning, you decide which of the two players is knocked out of the game.

You still have to worry about your bench and when to allow your pitcher to bat or not. But, you now give the manager a bit more flexibility. And if he wants to have a speedster on the roster, without thinking he’s burning through two roster spots (i.e., knocking out both the original catcher and Hamilton), he’s only burning through one.

What we have here is a rule that:
a. has no roster impact (you always lose a player)
b. is unobtrusive (no one is really going to notice anything)
c. allows the DH to disappear from the rulebook
d. gives the manager great flexibility

Downside? You tell me.

UPDATE: Based on one or two comments, I don’t think I was clear enough: at the end of the half inning, the manager chooses which player he loses for the game. In the above situation, if he goes for option c, he’d knock Hamilton out for the game, and the original catcher is allowed to stay. The same applies for a fielding sub: Hamilton could have come in as a defensive sub in the 8th inning in CF. At the end of the half-inning, the manager decides whether to knock Hamilton out of the game, or knock the guy he had replaced out of the game. There is NO “re-entry”. Someone will get knocked out of the game, just like it is today.