On the downside, using the Steam API seems to have removed data from two of the biggest games on the service. For some reason, Dota 2 and Team Fortress 2 don't seem to appear in our new, API-driven model, even though many other free-to-play titles seem to be measured just fine. This is a pretty major omission, considering that these games combined for over 46 million estimated players last April (and doubtlessly more today). We're not sure if this problem is on our end or Valve's. Regardless, their removal likely affects some of the 2014 sales and gameplay performance measured later in the piece.