When Altuve was called up from Double-A in 2011, he hardly walked. The keystoner drew just five walks and struck out 29 times in 221 at-bats that season and showed improvement in his All-Star year of 2012, walking 40 times and striking out 74 times.
"It's been phenomenal," Porter said. "He's gotten more at-bats and he understands now the value of counts, situations, when they're OK with walking him, and he's allowing it play out. His mental strike zone has gotten better, which is helping his strike-zone discipline."
Altuve has always had great hand-eye coordination, but he has grown up mentally as a hitter.
Brian McTaggart is a reporter for MLB.com and writes an MLBlog, Tag's Lines. Follow @brianmctaggart on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.