If the Yankees and Mets make it all the way to the end of October for a Subway Series, it will to a large extent be due to the similar philosophy they took at the end of July.

Both teams protected the best of their close-to-the-majors farm systems, did not add difference-making starters (or any starters) and instead deepened their pens to improve their playoff odds and then be able to play tournament baseball once there. And for good measure, both addressed their biggest positional needs, the Mets in center and the Yankees at third.

On Wednesday — the day before the deadline — when the Mets acquired Tyler Rogers and Ryan Helsley after already having obtained lefty Gregory Soto, an AL executive said, “The Mets clearly think they can win a World Series. They have built a championship bullpen, I think the best in baseball.”

When the Padres’ already brilliant pen added Mason Miller on Thursday, I re-inquired and the executive said, “If they keep [Robert] Suárez [which the Padres did], then it’s 1A and 1B, however you want to line it up.”