The rules for the convention were set last fall. 1237 is the number- if Trump does not reach it, he does not win the nomination and there will be an open convention. Trump cannot claim victory unless he wins. He was way behind the curve on his ground game and delegate management. He finally hired an establishment operative to help. Facts.
Rules are great. First rule is “don’t piss off the majority of your voters”.
All other rules are secondary.