The Reds’ plans for Aroldis Chapman’s role on the team have never really appeared to be fully fleshed out. First he was supposed to be a starter, but then team needs for the 2010 playoff run required another reliever. The opportunity to move him back into the rotation has never been seized since, and although there was much discussion of Chapman as the Reds’ fifth starter this season, he’s remained in the bullpen for the entire year. Starting remains an option for 24-year-old, and probably the best one for the team. If the Reds are going to keep Chapman in the bullpen, however, his usage so far this season serves as excellent blueprint.

Chapman has arguably been the best pitcher in baseball this season, particulary on a per-inning basis. Only a few other flamethrowing relievers, like the Yankees’ David Robertson and the White Sox’ Addison Reed have put up comparable numbers across the board. But Chapman may be the most impressive so far: he owns a spotless ERA, has struck out 21 batters against just nine baserunners (five hits, four walks), and he owns seven shutdowns without a meltdown and the top WPA among relievers in the league.

Chapman’s performance in any setup-type role would probably put him at or near the top of the WPA leaderboard, but Dusty Baker has done an excellent job of saving the most important situations for his best pitcher this season. Of Chapman’s nine appearances, six have come with at least a 1.0 average leverage index; three times that number has been at 1.98 or above. He’s pitched two innings on three occasions. By and large, outside of two games — 4/20 and 4/28 — where he needed work after a multiple-day layoff, the Reds have been using him in their most important situations or to cover multiple innings, starting in the seventh or the ninth or in extras depending on need.

The result may be a lower average leverage index (pLI) than relievers like Sean Marshall and Logan Ondrusek, but this is partially because Chapman has been so good as to avoid ultra high-leverage situations. Chapman has only allowed mutliple baserunners in an inning twice and only 16 times out of 47 batters faced has he dealt with runners on base. Chapman leads the team in entrance leverage index and inning-starting leverage index — he’s being used to prevent the fires in situations before the even start.

The Goose Gossage-type fireman hasn’t existed in the majors for a few years now, but if there was a solid candidate to revive it this season, Aroldis Chapman might be it. He is clearly one of the team’s most talented arms — probably the single most talented — and he needs to be used in a way that impacts the game more than the typical middle reliever. By picking his spots and using Chapman in the most crucial of situations, Dusty Baker has allowed Chapman to do just that so far in 2012.