Glenn Robinson III is still looking for the skeleton key to consistency -- the one that opens all the doors, brings out all his talents and sustains them for a stretch of games.

For much of the season, it's been Robinson's jump shot that's betrayed the Michigan sophomore. On one day, off the next, it comes and goes without discretion.

Robinson hasn't made a 3-pointer since U-M's Jan. 14 win over Penn State. Since then, he's 0-for-8 from behind the arc, but No. 10 Michigan (15-4, 7-0 Big Ten), in the meantime, has gone 3-0 with wins over No. 3 Wisconsin, No. 10 Iowa and No. 3 Michigan State.

The shooting woes haven't been a detriment to success, but have made some grow wary.

John Beilein isn't one of them.

"He's had really good shots and he's taken really good shots," the Michigan coach said Wednesday in advance of Michigan's Thursday night meeting with Purdue (13-7, 3-4) at Crisler Center. "I watch them go in -- he does a lot of shooting on his own. The next one he makes, he may never miss again. He's just going to keep on shooting it when he's open. He's a really good shooter."

It's been a tough season, though. In a six-game stretch from late November through December, the 6-foot-6 forward made 9-of-23 3-pointers (39.1 percent). For the rest of the season -- the six games before the stretch and the seven since -- he's 8-of-38 (21.1 percent). He's 3-for-18 in February heading into Thursday's last game of the month.

"Of course, the shots aren't falling," Robinson said Wednesday. "There's no doubt in my mind that those shots are going to fall just like they were a couple games ago and earlier in the season."

Robinson is 78 -of-129 on 2-point attempts (60.5 percent) on the season and averaging 13.6 points per game. Always a capable scorer in transition and on cuts to the basket, the bulk of his production has been at the rim.

With the jumpers not falling, Michigan would like to see more of that.

"Coach is drawing up more stuff for me to attack from the post and inside a little bit more," Robinson said. "When my shot doesn't fall, I try to go inside and get rebounds, so extra things to help the team out."

Rebounding, though, has followed a similar inconsistent path as Robinson's shooting.

Last week's win over Iowa was the paragon.

Active and everywhere, Robinson grabbed four defensive rebounds and four offensive rebounds in 17 first-half minutes. Then came the second half. Robinson grabbed one rebound in 18 minutes.

All told, he's registered four rebounds or less in eight of the last 12 games and has gone without an offensive board in four of last seven.

Thursday against Purdue (9 p.m., TV: ESPN) should present Robinson as the aggressor. His father , Glenn Robinson, was a two-time All-American as a Boilermaker and the 1994 consensus national player of the year with an average of 30.3 points per game.

The younger Robinson grew up in St. John, Ind., about 90 miles north of Purdue's West Lafayette campus.

"Being from Indiana and my dad playing there, there was a lot of talk about maybe I should have gone there, but there's no doubt in my mind that I'm at the right place," Robinson said. "I love playing against Purdue and IU (Indiana)."