Players betrayed by RNG rejoyce
http://i.imgur.com/KpDT0hd.jpgI
Why not have everyone start with 35% crit chance and -100% bonus crit damage.
Why 35%? , because too much of crit chance early game is "potential stat" one in 3 autos is a popular number in league for a reason because of the average window/duration you have in trades. no one will let you hit them 5 times if you're sitting on 20% crit. If they do they're probably already done for. Whereas early game tanks + cdr and base damage is always guaranteed dmg so if you can't have the potential gold your sitting on with crit chance not take effect in a trade then you are at a deficit.
just give everyone 35% crit from the start but reduce the crit for every %crit chance you have below 35%. starting at -100% crit damage at 0% crit. so cloak of agility would give you 20% crit chance + 57% crit dmg. why 35%, because 33.3333 = 1 in 3 and 35 is a close round number.
In the picture I made it so there's a cursor icon signifying to hover over to see the stats. A tooltip the appears showing both crit chance and bonus crit damage.
**Now bonus crit runes will actually be worth using on ADCs. **
The crit animation will only show if you have a minimum of 125% crit damage.
of course when you exceed 35% crit chance, crit chance increases instead of crit damage.