I think Zab would make it more of a fight. He would come more prepared, and try to box more. Plus, Tszyu is getting older, and may have conditioning problems{or not}. But, with Zab being a lefty. and Tszyu having a very good right, I still see Zab getting in trouble. I think the fight would look different. But, Tszyu can box also, and can hang with Judah if Judah gets in trouble or scared. If Zab could stay away, and force Tszyu to chase him, he could win a decision. However, I don't think Zab really wants any of Tszyu again, and would be intimidated, therefore Tszyu wins.