you get a crit on a body part then there's a roll on the crit table, high crits = cripple, low crits = more damage. You get a crit bonus based on luck so the easiest thing is blinding and the hardest is crippling arms. That's the real benefit of haymaker/more crits/finesse, crit bonus that applies to body parts. Better crits makes you much more likely to cripple.
Well if you look at the critical fail tables there's 6 possible outcomes dependent on your luck. so low luck you get something like the bottom four, high luck the top 4. Crippled would be the top tier, so if you have 10 luck and better crit it stands to reason that you'll hit the max bracket more often on the crit table. As for getting the crit in the first place, you have
Your LK does nothing with critical rolls, crippling and blinding, it only affects score critical hit or not, it doesn't affect critical roll or any other rolls in critical effect on your target.
Victim's LK gives protection against blinding, instakill and bypass, and EN against criplling and knocking down and out. Don't know what affect weapon drop, probably EN or nothing, but anyway there must be a roll, because it's not 100% drop even if attack to arm was critical.
Better criticals will allow to you atleast weapon drop chance if you critically hit target into arm, and more chance to score crippling critical, but anyway it won't affect victim's EN roll against it, so % to avoid crippling will be the same.
Better criticals is one of the best perks ever, so there must be no doubt taking it. Also with more than 100 critical roll into arm it shouldn't have a roll at all, and 100% cripple hand + 100% or roll on bypass and it's possible only with better criticals perk. Anyway bypasses into arms are common, so finesse for arms isn't that bad, because not only bypasses, but also damage into arms so low, so it's almost no difference between finesse and non-finesse, victim will laught at your damage anyway, so better criticals perk is good for crippler, well.. it's good for anyone who's going to do critical hits and criticals without this perk are... not good criticals, so it's must-have 9th level perk.
It gives 20 to critical roll, so you'll have 20-120 instead of 0-100, so you'll have only 1% (20) for lowest critical effect possible and 20% that you'll surely cripple hand and probably bypass. As I noticed every 2nd critical shot into hand is bypass, so it's like from 70 or 80 roll to bypass, means that without better critical you'll bypass only once out of 3 or 4 critical hits and with perk 1/2 of hits will bypass, of couse it's also dependant on target's LK.
Weapon drop has a roll and may be it's chance increases with higher critical roll, but anyway with better criticals perk you'll always start from 2nd critical effect atleast, so atleast weapon drop will be almost always if you scored critical.
60% Eyes
40% Head
30% Groin
30% Arms
20% Legs
(with 10 luck) plus more crits, finesse etc. with max possible crit(more if you are unarmed) being that plus 25% plus the 10% for luck(I think its not included in the bonus %)
so for arms you have basically 55-65% chance to crit, then maybe 1/3 chance to cripple (roughly)
for haymaker just tack on 15% to those calculations
Yes, it's not included, so with 10 LK you'll have 30+10-40 chance to score critical to arm. With Haymaker it's 55% and with x3 more criticals it's 70%, and with finesse it'll be 80%.
80% isn't that bad, because it's the same as sniper 10LK+x2 More critical shooting in the eyes.
The only problem that you'll be dead in 95% cases, because you aren't shooting but.. punching. It's good if you have a backup, and you're wearing bluesuit, so noone would care about you and while they are shooting your friends you'll cripple thier arms, but anyway it'll be easier to make SG/EW pistol build for crippling, and forget punching.