To Tank or Not to Tank: Defensive Stats in Season 3

Around the end of Season Two, certain top laners, supports, and most of the viable junglers acted as traditional tanks, using builds that emphasized resistance stacking in order to initiate fights. Popular top laners such as Shen went for Randuin's Omen and Wit's End to offer proper protection for diving onto carries, while junglers like Maokai and Amumu went towards tanky-damage items such as Sunfire Cape and Abyssal Scepter to offer every stat they needed. One Aegis of the Legion was essential, and general fell on the support (with some pro teams going double-Aegis on the jungler and support to give both champions double auras.)

With the start of Season Three, however, tanking has become a more difficult task. Overall, defensive stats had a cost increase. Cloth Armor lost three points of armor, Chain Vest lost five, and Frozen Heart lost nine. Items without specific numerical changes also got more expensive, such as Thornmail. These cost increase, along with related changes to the jungle and GP5 stacking, have made getting effective resistances a more difficult task.

While the price of resistances has increased, the general cost of health (the other important tanking stat) has decreased. Giant's Belt sits at a lovely 1000g (with a slight nerf), and build paths with it are cheaper, specifically Warmog's Armor. The removal of Warmog's “health per kill” feature transforms any champion into an instant tank, giving them 1000 health and insane regen as soon as they buy it.

This shift from resistances to health is made apparent in the purchase rates of both Warmog's Armor and the previous go-to item for end-game tankiness, Guardian's Angel. According to LoLKing statistics, since the 12/03 Preseason 3 Patch, Guardian Angel's purchase rate has gone down from 9.77% to 7.41%. Meanwhile, Warmog's Armor has gone up from 2.99% to 5.69%. Another key example is the recent Season 3 NA Qualifying matches, where most players started building Warmog's Armor around halfway through the match.

A graph showing the rate-of-purchase of Warmogs from 12/03 to 1/10 - Image courtesy of lolking.net

The biggest change lies in possibly the greatest buff of Season Three: armor and magic penetration. In Season 2, these stats (especially armor penetration) were hard to stack, and generally came at the cost of overall damage. Season Three both offered better items with penetration (Black Cleaver and Liandry's Torment) as well as fundamentally changed the mathematical calculations of how the stat worked (percentage based penetration now is counted before flat penetration.)

This ultimately makes the cost of resistances skyrocket. For example, an AP Champion with full magic penetration sits at around 50 flat penetration and ~42% penetration (not including Abyssal Scepter and champion abilities). If attacking a champion with 100 magic resist, their magic resist is reduced to ~8, lower than the starting stat of any champion. Here's another example: if an ability with full pen does 500 damage, someone with 2000 HP and 0 Magic Resist takes 500 damage, ending up with 1500 health. Someone with 1000 HP and 100 Magic Resist takes ~476 damage (after penetration), ending up with ~524. The champion with health can take four hits from that source, while the magic resist champion can take three. 

What this means is that for a champion to take 50% damage from an ability, they need ~270 magic resist, or ~220 magic resist from items at Level 18. This would require magic resist in every slot. Thus, the cost of offsetting penetration with resistances is more costly than just buying more health. While resistances are helpful for preventing "true damage", the cost of stacking them to create “effective health” is no longer as cost effective as creating actual health on your character.

While armor and magic resistance generally were free of diminishing returns in Season 2, the percentage-based penetration now makes stacking these stats less potent. 100 MR is ~8, 200 MR is ~70, and 300 MR is ~130; essentially, 100 MR past a base of 100 is only acting as 60 points of resistance.

Tanking, with these changes, is now a more thoughtful build to consider. While resistances are still helpful against opponents stacking damage, the increase in gold costs and newfound popularity of full-penetration spec'd AD assassins and mid laners has made resistance tanking more situational and less cookie cutter.