"The shift of the Astros into the AL West, a division that includes their state-rival Texas Rangers..."

"... will give each league 15 teams. All six divisions will then be inhabited by five teams."

Houston had long been an NL market. The Astros expanded into the NL as the Houston Colt .45s, along with the Mets, in 1962 and are about to celebrate their 50th anniversary.

MLB will realign for the first time since the Brewers moved from the AL to the NL in 1998, ushering in the era of Interleague Play with those games primarily fit into the schedule during May and June. The new 15-15 format will necessitate playing an Interleague game virtually every day...

"I came to 15-15 a little slower than many of my colleagues," [Commissioner Bud] Selig said. "I worry about that. I love Interleague Play... The fans enjoy it, which is all I really care about...."