Astros 2015 Opening Day: Meet Joe Thatcher, one of the newest Astros

On Saturday, the Astros finalized their 2015 roster, designating Alex White for assignment and adding both Roberto Hernandez and Joe Thatcher to the Opening Day roster.

Who is Joe Thatcher, though? How did he go from non-roster invitee and minor-league signing to the big league bullpen? Let's find out.

Origin story

No, Joe Thatcher isn't Brian McTaggart's long-lost brother. He's also not the descendant of Heath Ledger's character from A Knight's Tale, though I'll allow nicknaming him "Sir Ulrich Von Lichtenstein."

He is an Indiana native who went to Larry Bird's university, Indiana State. Thatcher was not drafted at any time, either out of high school or in either of his two final years in college.

He did want to continue playing professional baseball and so he joined the independent River City Rascals in O'Fallon, Missouri in 2004. He threw 42 innings that season with a 2.98 ERA, 55 strikeouts and five saves.

Thatcher went back to River City in 2005, when he was signed out of the Frontier League by the Brewers. He quickly moved through Milwaukee's system, making it to Double-A the next season and made his major league debut in 2007.

In July of 2007, Thatcher was traded to San Diego in the Scott Linebrink deal (another Astro alert!), along with WIll Inman and Steve Garrison. It's the first of three different deadline deals in which Thatcher has been included.

He went up and down twice with San Diego, pitching in the minors and majors in both 2007 and 2008 (plus 2009, 2010, 2011 and 2012). Some of those trips down were rehab assignments, but as a LOOGY, Thatcher had a long road to stick in the majors.

He has pitched in at least 50 games in the majors in five of the past six seasons. In 2013, he was traded along with Matt Stites to Arizona for Ian Kennedy (which seems like an incredibly bad deal). Last summer, he was flipped by the Diamondbacks to the Angels along with Tony Campana for two minor leaguers.

Last year

Between the Angels and D'Backs, Thatcher threw 30 innings in 50 games, striking out 27 while walking four. He had a 3.86 ERA in those innings, but was much better in Arizona than he was in Los Angeles (or Anaheim).

With Arizona, he struck out 25 in 24 innings and had a 2.63 ERA. He only gave up 23 hits and three walks with the Snakes. In six innings with the Angels, however, Thatcher got blown up, giving up 13 hits and six runs while walking one and striking out two.

Finally hitting free agency last winter, Thatcher couldn't find a team to give him a major league deal, so he went to Houston. His bet paid off, as Thatcher was added to the roster last week.

What he throws

The lefty works off two main pitches. He's got a cut fastball that he throws about 70 percent of the time. The pitch dives in on lefties and has plenty of sink to it.

His slider breaks away from lefties with about three inches more drop than his cutter.

Against left-handers, he throws the fastball/slider combo with a 65/35 split. Against the rare right-hander he faces, Thatcher relies almost exclusively on the cutter.

Splits

Whatever pitches he throws, Thatcher has been death to lefties in his career. The 33-year-old has a 157 strikeouts in 119 career innings against left-handers. He sports a .222 opposing batting average to lefties in just under 500 career plate appearances.

While his splits are wildly successful against lefties, he's been less so against right-handers. Thatcher's strikeout rate plummets against batters on the right side, but his walk rate is nearly 50 percent.

That's less of a sample size issue, since he's actually faced more right-handers in his big-league career than lefties.

Though Thatcher will be much more effective when deployed against sinister batters, he's more than capable of pulling a Tony Sipp and being an effective reliever in whole inning packages.