Influence of gameplay on skill in Halo: Reach

Huang et al. Influence of Gameplay on Skill in Halo Reach, 2013

Data: 3m player data (entire population) for the first 7 months of Halo Reach, and 70 players in a survey. Mixed methods: use survey data to help explain the big dataset.

Most played mode is Team Slayer: from 3v3 to 5v5, one point per kill, first team to reach 50 kills. Match ends after 15 min.

Player skill metric: TrueSkill's mean μ. More frequent players have bigger μ drop at week 1, but their μ increases faster over the weeks.
The longer the break between two games, the bigger drop in skill. It takes 10 games (3h of gameplay) to regain the skill lost after a break of 1 month.
Most of the top 100 players use the DMR (same range as sniper rifle) and sniper rifle.