It's 89% and it's over 4 years. That wasn't an issue for them given my back of the envelope math. They were close to the cap in 2014 and 2015 - 99% and 95.5% respectively. they were at 86% and 88% in 16 and 17 before going about $22M over what the league cap in 2018 was.
You're right here. I didn't quite make the point I wanted to make when I initially brought this up. These contracts are generally more team-friendly in a front loaded fashion because when you front load a contract, you normally have to give up less guaranteed money. The player getting his guarantee all in the first year of the contract gives them present value of that money and strengthens your negotiating position for less guaranteed money. Less guaranteed money=more cap space.
Also it's a forced financial discipline in making future decisions. If you amortize the guaranteed money, while effectively the same guaranteed money against the cap, it MIGHT force you into keeping a player you would otherwise cut and effectively guaranteeing more money (the salary he makes by keeping him). By pre-paying that money, even if you roll over the cap effectively, some front offices -- especially if they are worried about their jobs -- might not want to cut a player and have dead money (even if it's more of a PR issue). And if that happens you've now guaranteed more money in the actual salary.
In a lot of ways I'm saying pre-paying the cap money has the benefit of keeping a possibly undisciplined front office, more open to all their options.