MLB DH question
 

I confess to not being familiar with OBR DH rules, or if MLB (AL) treats it differently.

Scenario: In the lineup, Smith is DH, batting 7th; Jones is C batting 8th.

A: In the 6th inning, Joe Mauer bats for Smith and gets out ending the inning. Manager tells PU he wants Mauer to play catcher, and replaces Jones with Johnson at DH, batting 8th. Legal?

B: In the 6th inning, Manager approaches PU to make a "double switch" - simultaneously putting in Mauer in the 7 hole to catch and Johnson in the 8-hole to DH. Legal?

A. No. When Mauer (the new DH) enters the game on defense, the role of DH is done for the game. The pitcher must bat in the replaced catcher's spot.

B. No. The DH must bat in the 7 hole all game.

OBR 6.10 "The Designated Hitter may be used defensively, continuing to bat in the same position in the batting order, but the pitcher must then bat in the place of the substituted defensive player, unless more than one substitution is made, and the manager then must designate their spots in the batting order."

In A and B I agree with dash.

Also in B the pitcher would have to hit in the 8-hole.

A. Joe is new DH. Joe can play catcher if he replaces Pitcher he was DH for. DH terminated. New pitcher would need to come in for someone else, likely the batter before Joe. Jones can't be replaced with a new DH. B. Joe can only DH in the original DH hole, can't change.

Double switch is something used in National League because no DH rule. Replace a pitcher and position player at same time so pitcher bats 9th coming up.

OBR 6.10 "The Designated Hitter may be used defensively, continuing to bat in the same position in the batting order, but the pitcher must then bat in the place of the substituted defensive player, unless more than one substitution is made, and the manager then must designate their spots in the batting order."

Double switch is used in the American League too, just not for the same reason, and not involving the pitcher. You've seen teams put in more than 1 defensive sub at a time, and they don't have to bat the new LF in the old LF's slot, the new 2B in the old 2B's slot - the better hitter will go in the slot that's batting soonest. Same deal.