The power of the major league manager is in decline, and the role has changed in baseball’s information age. More and more power is concentrated in the front office, which constructs rosters and sets organizational philosophy. Yet there’s one traditional managerial responsibility that remains largely intact: in-game decision making. While the front office plays a role in game-planning in most organizations, the manager is ultimately making the real-time decisions. Tactical errors can be lost in the marathon of a regular season, but they are heightened and highlighted in the postseason.New York Yankees manager Aaron Boone had a tough Monday. His Tuesday wasn’t much better. And in part because of his decisions, the Yankees’ season came to a close. The Boston Red Sox advanced to play the Houston Astros in the American League Championship Series beginning Saturday in Boston.The Yankees entered the postseason with the most dominant bullpen in history by some measures, including wins above replacement (9.7) and strikeout rate (11.4 strikeouts per nine innings). Moreover, managers have never been more aggressive in employing their bullpens. Major league relief pitchers accounted for a record 40.1 percent of innings in the regular season. They absorbed a record 46.5 percent of innings last postseason. Entering LCS play, relievers have accounted for 48.8 percent of innings this postseason. But Boone seemed to forget that Yankees general manager Brian Cashman had spent the last two years building one of the most dominant relief units of all time.After Sunday’s off day, with the series tied at 1-1, the Yankees started ace Luis Severino in Game 3. Severino struggled. The Yankees already trailed 3-0 in the top of the fourth when three straight Red Sox reached to open the inning and load the bases.“Certainly in hindsight, when he doesn’t get an out, I’d like to have that back,” the rookie manager told reporters before Game 4 on Tuesday. “Being able to look back in hindsight, sure, go in a different way there.”At that point, the Yankees had a 10.2 percent win expectancy, according to FanGraphs. Boone then exacerbated matters by calling upon Lance Lynn, hardly the top bullpen option available, with a 4.77 ERA in the regular season.1Though he pitched better with the Yankees (4.14 ERA) than he had with the Twins (5.10). Lynn walked Mookie Betts and allowed a bases-clearing double to Andrew Benintendi. The Red Sox led 10-0 by the close of the frame, and the Yankees’ win probability had fallen to 0.8 percent, en route to their 16-1 loss.Source: FanGraphsAny decision from Boone in that situation might not have changed the final outcome. The next pitcher after Lynn — Chad Green, a more dominant bat-missing arm — also struggled. But Boone’s curious thought process played a part in letting the game slip away early.“I know it’s out there because of the texts I receive, the ‘hang in theres,’” Boone told reporters about the second-guessing. “We can all sit and second — not even second guess, first guess or second guess — I would do this, that’s one of the great things about our game.”On Tuesday night, as the Yankees faced elimination, some in the media advocated for the Yankees to bullpen the game. Boone started veteran CC Sabathia and stuck with him through a third inning in which the Yankees’ win probability slipped from 50 percent to 23.9 percent.Source: FanGraphs Yankees ace reliever Aroldis Chapman did not pitch Monday and only appeared Tuesday when the Yankees were down by three runs in the ninth inning. In the Yankees’ five postseason games, including their wild-card game win over the Oakland A’s, Chapman pitched just three innings.Meanwhile, in the year of the relief pitcher, the Milwaukee Brewers have bullpenned games in the postseason, and the Tampa Bay Rays, a rival of the Yankees in the AL East, often started regular-season games with a reliever. The Red Sox used ace Chris Sale in relief Tuesday. But Boone plotted a more traditional path — and it cost him.Managers have lost power, but they have become important conduits and gatekeepers when it comes to sharing and embracing information. While their power is reduced, their decisions can still make or break fortunes.Check out our latest MLB predictions.