Some of the more conspiracy-prone Dota discussion areas are pretty skeptical that Dota2’s matchmaking is effective, and in some extreme cases they doubt it even exists. So I did a bit of analysis on the types of games each bracket and can demonstrate that there are definite trends in player performance between the brackets. This in no way proves that Dota 2’s current matchmaking is flawless, but it does suggest that it’s been successful in sorting by player skill level.
One inconvenience you’ll have to forgive, due to technical difficulties these charts are legendless. In all the charts, the red line is the Very High bracket, the green line is the High bracket, and the blue line is the Normal bracket.
One other tiny, almost irrelevant factor: the ends of the distribution tend to be larger as an easy way of handling extreme outliers without warping the graph. As far as I’ve been able to determine, this simplification is entirely inconsequential.
Disclaimers aside, I give you the distribution of games by duration:
The mean match duration for the sample is:
vh = 38.46 minutes
h = 40.22 minutes
n = 44.10 minutes
Normal games, on average, last significantly longer than games in both the High and Very High bracket. No real surprises here. More highly skilled players tend to emphasize push and gank strategies over farm strategies, and they’re more capable of closing games once they have a significant advantage.
Moving on, we have average GPM:
The mean GPM for the sample is:
vh = 344.75
h = 330.19
n = 307.27
Again, no real surprise. From what I’ve seen, last hitting is the skill that is the most consistently improved as you move up in the skill brackets. You often see complaints about low skilled players leaking into the High and Very High brackets. In most cases, this is simply the result of group queuing, but it’s possible that there’s a class of player who wins more often than not in the Normal bracket simply by having superior last hitting mechanics than the competition. This moves them into the higher brackets where their relatively undeveloped game sense gets exposed by the shift towards more aggressive strategies.
Now for XPM:
Mean XPM in the sample:
vh = 445.51
h = 435.67
n = 422.20
This increase is less pronounced than GPM, which again, isn’t very surprising. An XPM increase mostly reflects an enhanced game sense for finding time to farm. This might entail using a TP scroll to a tower that’s about to receive a creep wave. This might come from remembering to stack and pull as a support. This might come from knowing when and how to use neutral creeps to enhance your farm. All these are important skills, but they’re skills that are already reflected in GPM. GPM adds in the mechanical aspect of last hitting, so GPM will be the stat that’s more sensitive to player skill.
Finally, we have Deaths per Minute:
Average Deaths per minute:
vh = 1.72
h = 1.65
n = 1.60
Of all the statistics, Deaths per Minute sees the smallest shift between the Normal and Very High brackets. Does this contradict what I was saying about Very High players being significantly more aggressive? No. Instead what’s happening here is that Very High players are better at playing aggressive, but they’re also significantly better at playing it safe. The skill increases counteract each other, but aggression gradually edges out safety to make for a slight trend towards higher kill scores.
One possible curiosity that stands out is that in this graph, Normal and High have very similar lines. In all the other graphs, High and Very High had the most similar lines and Normal was the outlier. A tentative interpretation is that as a player learns more about the game and moves up in the brackets, they’re more likely to first improve their farming skill and death prevention than they are their aggression and ganking. Exceptions would exist of course, possibly in great numbers, but the cautious farmers would still be the majority in the High bracket and therefore have the largest statistical footprint.
With this out of the way, it’s likely time to move on to one of the more interesting, and possibly most misleading metrics, creep kills per minute.