As noted especially this time of year, March Madness is all about guard play and the vast majority of teams who go deep in the tourney have excellent guard play. Teams with a few successful "bigs" with average guard play don't advance beyond the first weekend typically.
Re: defense, yes...effort, concentration and technique can be taught to improve defense however speed and athleticism is part of that equation too. It's like yelling at my 5th grade team I coach to box out better, however we play a lot of zone and it's simply more difficult to box out in a zone (defending space vs. a player) vs. man. However when we play man we get beat off the dribble. Pick your poison although I'd argue I'd rather see 2's go in vs. 3 after 3 after 3 when Fran won't get out of zone.
Re: defense, yes...effort, concentration and technique can be taught to improve defense however speed and athleticism is part of that equation too. It's like yelling at my 5th grade team I coach to box out better, however we play a lot of zone and it's simply more difficult to box out in a zone (defending space vs. a player) vs. man. However when we play man we get beat off the dribble. Pick your poison although I'd argue I'd rather see 2's go in vs. 3 after 3 after 3 when Fran won't get out of zone.