Mattingly is tied with Showalter at +700 odds for next Astros manager. He too would be a mistake of a hire.
In 12 years, Mattingly is 889-950 as a manager. His below .500 record is slightly misleading, as he went 446-363 while leading the Dodgers, before being tasked with managing a Marlins team that was forced into a rebuild after the Jose Fernandez tragedy.
Never the less, it is inarguable that both the Dodgers and Marlins took steps forward without him.
Dave Roberts almost immediately got the Dodgers over the hump, taking them to the World Series in three of his first five seasons. The Marlins went 69-93 last year in Mattingly's final season, traded away their co-ace in Pablo Lopez, and then went on to win 15 more games and make the playoffs.
Mattingly is a lifelong, "baseball guy." But his on-field resume is much better than that of his managerial resume. Mattingly should not be the Astros next hire.