Not knowing a whole lot about Showalter, I went to Baseball-Reference to hopefully get an idea about his previous coaching results. In head coaching stints with three teams -- the Yankees, Diamondbacks, and the Rangers -- Showalter has a career record of 882-833. He's also been named AL manager of the year twice: in 1994 with the Yankees and 2004 with the Rangers.
One of the strangest things about Showalter's managerial career -- and this is also mentioned on his Wikipedia page -- is that the Yankees (in 1996) and the Diamondbacks (in 2001) both won the World Series the year after he was fired. Showalter also very nearly was fired three times while still having winning records: 79-65 (1994), 85-77 (2000), and 80-82 (2006). Close, but no cigar.
Showalter is an interesting choice for the Orioles, and arguably his most important task will be to get more production out of the team's younger players. Highly regarded prospects like Brian Matusz, Matt Wieters, Adam Jones, and others have shown promise and seemingly have the talent to produce at the Major League level, but they haven't been able to put all of the pieces together yet. Maybe Showalter, who himself moved up the coaching ranks in the minor leagues before becoming the head coach of the Yankees, will do a better job of helping them get to the next level.
By the way, in case you're wondering, Showalter is definitely an old-school type manager. Just check out this 1994 article in The New York Times about Showalter's criticism of that young hotshot Ken Griffey Jr.:
It's not Mariners versus Yankees in Seattle this weekend so much as Griffey versus Showalter, perhaps the game's premier player against one of its brightest young managers in a lively discourse on the merits of respecting the game.So even if Showalter can't get the O's to improve much on the field, at least fans won't have to worry about any untucked shirts or caps being worn backwards.
"I shouldn't say this publicly," Showalter was quoted as saying in the magazine story, "but a guy like Ken Griffey Jr., the game's boring to him. He comes on the field, and his hat's on backward, and his shirttail's hanging out."
He also made pointed comments about San Francisco's Barry Bonds, saying that at last year's All-Star Game Bonds failed to tuck in his shirt until game time.
"To me, that's a lack of respect for the game," Showalter said. "Maybe I'm being too picky on these guys. I'm starting to say things like, 'Back when I played.' I thought I'd never say those words."