At his height, there’s no way Isaiah Thomas should be able to score as well as he does. The odds are certainly stacked against him considering only two players in NBA history under 6-feet have ever averaged 25 or more points in a season: Calvin Murphy for the Rockets in 1977-78 (25.6 points) and Michael Adams for the Nuggets in 1990-91 (26.5 points). Thomas is currently averaging more points than both them (27.8 per game) on a much greater effective field goal percentage and true shooting percentage.
Other than saying there isn’t much he can’t do on the court, it’s hard to pinpoint what exactly makes Thomas such a difficult matchup for defenders.