Came across this thread on the Dota 2 subreddit a few days ago. The OP is now deleted, but it got me wondering how things had changed since this old spreadsheet from who knows what ancient patch.
For a lot of reasons item win rates kinda suck as a statistic, but one of the biggest is that expensive, late-game items will often have inflated win rates due to being luxury pickups that are primarily bought by the stronger team to close the game (and conversely, cheap early game items will have low win rates simply because they’re most likely to be sold/disassembled/converted). If we could control for different factors like purchase time, item win rates could be at least a bit more useful. Unfortunately, that information is not available.
So as a next-best, mediocre workaround, I tried plotting the win rate increase in Aghanim’s games with the purchase rate of Aghanim’s for that hero using Dotabuff’s stat listings. The idea being here that heroes that pick up the item more often likely tend to, on aggregate, view Aghanim’s as a more core pickup, and therefore should tend to pick it up earlier in their item progression and see less of a luxury inflation to win rates with the item.
As an illustrative example, Invoker’s build Aghanim’s in just under 90% of their games on Dotabuff. Invoker also receives the second smallest win rate boost from owning an Aghanim’s. Regardless of how good you view his Aghanim’s upgrade, this makes sense because if Invoker built it in 100% of his games the win rate increase from the item would necessarily be 0%. In general we would expect the item’s win rate to increase the less often it’s built, and this appears to be the case more or less when you plot out all the heroes.
So the basic idea we’re left with is that the heroes whose win rates beat this trend the most decisively will tend to include the ones with the strongest effects, and the heroes that fall below will tend to include the weakest.
I say “tend” because the title’s a bit of a lie, but you try being sufficiently nuanced under that kind of character limit. This isn’t a diagnostic that gives us a definitive answer on which ugprades are good or bad, but it does provide us an idea of where to start looking if we decide to investigate further.
For example, Slark scores really highly. He also has less Aghanim’s purchases in the last week than Tiny, a hero who no longer has an Aghanim’s upgrade. On top of this, it’s possible that when people do pick up Aghanim’s on Slark, they do so with the intent of making it easier to kill the opposing Ancient and close a game that was already won. Whatever the cause ends up being, it’s likely that the results from heroes with very small samples are not especially reliable.
Conversely, the Aghanim’s win boost on heroes like Visage and Invoker maybe don’t live up to common expectations. This doesn’t mean that the expectations are necessarily wrong. It could be that these upgrades are hard to use effectively and perform better in brackets 4k and above. Or it’s an upgrade that’s situationally good, but is either built too often or too early by the playerbase at large, and similarly performs better in the higher brackets where people are more aware of why they’re building the item. Skill level is one of the big things that the Dotabuff data doesn’t include, so keep that caveat in mind as you scroll past this text without reading so you can get to complaining in the comments that I’m telling people to rush Aghanim’s on Slark and never build it on Tinker.
Anyway, here’s the results:
Best Performers: (Aghanim’s Usage rate/increase in win rate (yes, I’m absolutely too lazy to go back and paste in column headers))
|Queen of Pain||25.93%||7.86%|
Best Performers with at least 10% Use Rate:
Best Performers with at least 25% Use Rate:
Here’s all the raw data
And here’s the graph that somehow manages to be both comically oversized and unreadable at the same time.
And for what little it’s worth, people might be underestimating Meteor Hammer on at least a situational basis, and Spirit Vessel’s win rate looks crazy good given the purchase price. Would be completely unsurprised to see an eventual nerf on the latter.