Coaches are stubborn, must stay with their "system"
Because coaches are stubborn and if pressing isn't "their thing", if it isn't what they do on a regular basis, they won't do it until they absolutely have to (see Izzo's decision to finally press Gophers when Sparty's back was firmly against the wall at 47-40 with 4 minutes left).
Michigan absolutely should pressure our guards from the get-go on Saturday, but I'll bet you they won't because Beilein (a quality coach & tactician like Izzo) prefers the 1-3-1. They'll put serious heat on us only if they fall behind.
Weber at Illinois did it the right way. It wasn't the prettiest game by the Illini, but if I recall correctly the Illini applied a lot of pressure on Blake from the get-go. They made it as difficult as possible for Blake. That's what I'd do if I was playing the Gophers now. Since Al went down I'm sure glad most teams have chosen not to press us. It's the simplest way to beat us, and I say that with no direspect toward Blake. He's just not a true PG, as we all know