How deep are the Dodgers? So deep that Hyun-Jin Ryu, who sports a 1.54 ERA since the all-star break, could be without a role in the playoffs. (Charles LeClaire/USA Today)

PITTSBURGH — Alex Wood had just settled into the Los Angeles Dodgers’ dugout at PNC Park at the end of the sixth inning Monday night when Manager Dave Roberts came over to say he planned to send up a pinch-hitter for him in the top of the seventh, effectively ending Wood’s night after 86 pitches. At the time, Wood had retired six straight Pittsburgh Pirates batters, and 11 of the last 12. With a little run support, he might have been headed to his 15th win of an all-star season.

The next day, Wood went on the 10-day disabled list with inflammation near his collarbone.

It was just another 24 hours in the life of the Dodgers’ 2017 starting rotation, a fascinating experiment in modern game- and roster-management, in which the starts are generally short, rest is plentiful and the DL is effectively a glorified waiting room where the Dodgers – a $250 million juggernaut with a 90-36 record, a 21-game lead in the National League West and a chance to be among the winningest teams in history — stash their extra arms until they’re needed again.

“We have a lot of moving parts,” Wood shrugged at his locker Thursday, wearing an electrotherapy device on his sore sternoclavicular joint.

Now on a 116-win pace that could see them challenge the 116-win Seattle Mariners of 2001 as the best team this century, the Dodgers are revolutionizing the time-honored notion of the starting rotation. Blessed with almost unlimited resources and a bullpen that ranks among the best in the game, the Dodgers rejected the old ideal of riding five horses for 200 innings each, preferring a model in which six or seven interchangeable starters — plus throwback ace Clayton Kershaw — each throw something closer to 150.

“When you have so many good players,” Roberts said, “you have the luxury of not having 200 innings be the norm or the benchmark, like it always has been for a starting pitcher.”

The Dodgers’ approach stands in stark contrast to that of the National League’s second-best team and their potential NL Championship Series opponent, the Washington Nationals. The day before Wood’s typically abbreviated, 86-pitch start in Pittsburgh – which was right in line with Wood’s average of 87.6 pitches per start this season — Nationals Manager Dusty Baker left veteran left-handed Gio Gonzalez in for 121 pitches in a 4-1 win at San Diego. It was the fourth time this season a Nationals starter had thrown at least 120 pitches, twice as many times as any other team in the game and four more than the Dodgers.

Another way to highlight the contrast: The Nationals have used their starting pitcher for 100+ pitches a total of 85 times this season, second-most in the majors. The Dodgers have done so only 23 times, 28th in the majors. Even when veteran lefty Rich Hill, carrying a no-hitter at the time, was allowed to pitch into the 10th inning Wednesday night, he didn’t reach the 100-pitch plateau. He lost the no-hitter and the game on a walk-off home run on his 99th and final pitch.

“I think Dusty is old school,” Wood said of the Nationals’ manager. “He gives the starter the ball and says, ‘Here ya go. It’s your game.’ Here, it’s more new school. If you’re shutting [the opponent] down, you’ll go as long as you can. But if you start to see a little trouble in sixth, [the bullpen is] going to get loose. It’s a happy medium between what’s smart and going by the numbers, but also having some feel based on how well a guy is throwing throughout that game.”

The Dodgers also rely on their remarkable depth – as well as the 10-day disabled list – to give their pitchers extra rest between starts on a regular basis, which also keeps their innings count down. This season, their starters have pitched on more than four days’ rest on 87 occasions, the most in the majors; the Nationals’ starters have done so 66 times, tied for 12th.

In large part, the contrast between the Dodgers’ and Nationals’ approaches comes down to personnel. The Dodgers have a deep and effective bullpen; until recently, the Nationals’ has veered between inconsistent and awful. Meantime, the Nationals boast five starters whose track records each include at least one 200-inning season; the Dodgers have only two – Kershaw and newly acquired right-hander Yu Darvish.

While the approaches are vastly different, it’s difficult to say one is better than the other. As measured by ERA, the Dodgers own the best rotation in baseball (3.21), while the Nationals’ ranks second (3.50).

“It really is dependent on the personnel you have, whether you’re able to do it this way,” Kershaw said Thursday. “With Washington, you saw earlier in year their bullpen was struggling so much – now it’s a little bit different — and they also have big horses [in the rotation]. You can compare and contrast all you want, but it’s just two completely different staffs.”

But clearly, for the Dodgers, the approach is more than a matter of happenstance. It is also an organizational philosophy based largely on one theory and one fact. The theory: Pitchers are fresher for the postseason if they haven’t been ridden for 200-plus innings in the regular season. Yes, the Dodgers’ financial resources allow them to do things – such as paying eight starting pitchers in excess of $2.8 million this season, including five making at least $11 million, and then using them more or less interchangeably –  that less fortunate teams can’t do.

“We have the depth to do it,” Kershaw said. “We have a bunch of starters. With the lead we have and the starters we have, we can make sure guys are fresh. It’s a luxury, for sure.”

The fact: Starting pitchers generally lose effectiveness with each trip through an opposing lineup. This season, MLB starters have limited opposing batters to a .736 OPS on their first time through the lineup, but those numbers go up to .783 and .800 on the second and third times through, respectively. By contrast, relievers have limited opposing batters to a .721 OPS their first time through a lineup. Basically, unless your name is Kershaw, the Dodgers believe they have better options than you in the late innings – which is why their other starters rarely exceed 100 pitches or six innings.

“If the numbers show that the third time through the lineup, the OPS goes through the roof, and if you have a lot of good arms in the bullpen,” said Brandon Morrow, the Dodgers’ veteran right-handed reliever who was primarily a starter from 2009-15, “then it’s not a bad strategy to use.”

Roberts, 45, recalled being indoctrinated in the Dodgers’ roster-management philosophy shortly after taking their manager’s job before the 2016 season, and being presented with all the statistical evidence behind it.

“A lightbulb went off, and it made so much sense,” he said. “Our front-office guys are ahead of the curve.”

But such an approach requires a degree of buy-in on the part of the Dodgers’ pitchers. To a large extent, a pitcher’s current and future salaries are determined, via the arbitration system, on the basis of durability and workload, and when those attributes are artificially depressed by an organizational philosophy such as the Dodgers’, there could be a financial impact.

“For us, from the starting pitchers to the position players to the relievers, there has to be unselfishness,” Roberts said. “Ultimately, players want to perform and get opportunities to take care of their families and be compensated. That’s natural. But there has to be some sacrifice to make this whole thing – our vision as an organization — work …. Yes, we have depth, but that depth wouldn’t play out the way it should if the players don’t buy into it. And they have.”

Wood’s latest trip to the disabled list was the 37th such stint by a Dodger this season, according to data at RosterResource.com, by far the most in the majors. At the time, he was one of 13 Dodgers on the DL, including an entire rotation’s worth of starting pitchers – Wood, Kershaw, Darvish, Scott Kazmir and Brandon McCarthy.

It isn’t that the Dodgers are faking injuries – the process requires medical certification of the injury, as well as MLB approval, and especially this time of year nearly every pitcher can truthfully say some part of their body is bothering them – but at least in some cases, they place pitchers on the DL with tweaks or twinges they might otherwise pitch through, were they on another team. With the minimum stay reduced from 15 to 10 games this year, a starter can go on the DL the day after he pitches, return 10 days later and effectively miss just one start.

“If we weren’t up 20 games, I wouldn’t have gone on the DL,” Wood said of his current injury, which he said has been a “nuisance” in recent weeks. “But we had the luxury of skipping a start and giving it a chance to get better. We’ve got a lot of good arms.”

The idea, of course, is to have everyone healthy and fresh by October, but that presents its own set of issues. Darvish is expected to come off the DL on Saturday, and Wood and Kershaw could be back in another week or so, resulting in a logjam of pitchers. By the postseason, when teams typically use just four starters, someone such as lefty Hyun-Jin Ryu, who sports a 1.54 ERA since the all-star break, could be without a role.

“That’s the thing we have to deal with when you have a lot of good players,” Roberts said. “There’s going to be some tough conversations.” With a laugh, he added: “It’s a high-class problem, man. I like high-class problems.”

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