NEW YORK — The postponement of Wednesday night’s scheduled Game 4 of the American League Championship Series on account of rain is no big deal on a surface-level — a delay of 24 hours, with the game now scheduled for Thursday night at Yankee Stadium. An inconvenience for fans, sure. A break for weary arms and legs. A condensed schedule for the rest of the series, which could still go seven games. No biggie — baseball is designed to be a daily game.

But on a deeper level, one simple rainout changes almost everything about the ALCS, which the Houston Astros lead 2-1 over the New York Yankees — all because of one factor: the ample rest required of elbows and shoulders that propel baseballs through the air at speeds of 100 mph or higher.

This is the new schedule: Game 4 on Thursday night at Yankee Stadium, followed by Game 5 on Friday night (previously a scheduled travel day). Then Games 6 and 7, if necessary, at Houston’s Minute Maid Park on Saturday and Sunday nights. The winner of the series will host the Washington Nationals, champions of the National League, in Game 1 of the World Series on Tuesday night.

But here are the larger ramifications, and they are many:

In the short term, the rainout appears to benefit the Yankees, who were prepared to attack Game 4 as a bullpen game, with a relay of pitchers going one to three innings each, then handing the baton off to the next guy. Instead, they will be able to use right-handed starter Masahiro Tanaka, their October ace, on his regular four days’ rest. In Game 1, Tanaka needed just 68 pitches to shut out the Astros for six innings. Lefty James Paxton is likely to start Game 5 for the Yankees.

Tanaka will be facing Astros right-hander Zack Greinke — a former Cy Young winner but one whom the Yankees hit hard in their Game 1 win. This is an upgrade for the Astros, as well; they were expected to start rookie Jose Urquidy in Game 4 (or perhaps use an opener to precede Urquidy) before the rainout allowed Greinke to collect an extra day of rest.

* In most other ways, the rainout appears to benefit the Astros. They will start veteran ace Justin Verlander on regular rest in Game 5 on Friday, Manager A.J. Hinch announced Wednesday afternoon. That gives them the further flexibility to start Urquidy in Game 6 in Houston, or, if they lose both Games 4 and 5, bring back co-ace Gerrit Cole on short rest — something Cole has never done in his career. If the Astros are leading the series heading into Game 6, they almost certainly would hold back Cole as their firewall in Game 7, on full rest.

But the essential math for the Yankees remains the same: To win the series, they will have to win at least one game started by either Verlander or Cole, who are the co-favorites for the AL Cy Young Award and a combined 4-1 with a 1.58 ERA this postseason. Cole has not been beaten since May 22, going 19-0 with a 0.59 ERA.

* The Yankees’ strategy of riding their bullpen to postseason glory — a strategy predicated in large part upon the prevalence of days off in October — takes a large hit from the rainout, because the new schedule could require four games in four days if the series goes the distance.

Would the Yankees ask their best arms to pitch on four straight days? That seems untenable given everything we know about relievers’ ability to bounce back over multiple days of usage in a row and unlikely given the way the Yankees have deployed their top relievers this season. Here are the number of times Yankees Manager Aaron Boone called upon his most trusted relievers on back-to-back days in the second half of 2019:

Aroldis Chapman: 6. Chad Green: 1. Adam Ottavino: 6. Zack Britton: 5. Tommy Kahnle: 7. But here are the number of times, combined, any of those five relievers pitched on three consecutive days: 0.

“We’re going to have to get some innings out of our starters,” Boone said on a conference call with Yankees beat writers on Wednesday. “There’s no question about it.”

* There may be some room for debate as to whether the Yankees or Astros benefit most from the rainout, but there is little doubt that the biggest beneficiary of all is the Nationals — who, by virtue of their sweep of St. Louis in the NLCS, have a week to rest and recuperate while the Yankees and Astros are beating each other up for as many as four more games.

The Nationals, of course, are better positioned the deeper the ALCS goes; their best-case scenario is the Astros and Yankees going to a decisive, all-hands-on-deck Game 7, leaving the survivor drained and depleted less than 48 hours before the first pitch of Game 1 of the World Series.

The Astros’ strategy of using Verlander on regular rest in Game 5 Friday night, rather than saving him for Game 6 in Houston on Saturday night, as previously scheduled, is probably designed to facilitate their own best-case scenario — which is to win the ALCS in five, behind Greinke and Verlander, and thus have Cole (on extra rest) lined up for Game 1 of the World Series, followed by Verlander (on regular rest) in Game 2.

There is plenty of baseball left to be played this month, and there are plenty of permutations of pitching deployment to weigh and debate. The rainout Wednesday at Yankee Stadium doesn’t only delay things, it scrambles them, leaving only one entity unscathed and unbothered by these developments: the Washington Nationals.

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