Guillen’s Sox, especially at the end of his line, became a wasteful enterprise. They ran too much. They bunted too much. They intentionally walked too many batters. They gave up too many steals. When a team freely forfeits that many at-bats, outs and bases in either half-inning, it puts a lot of pressure on the talent. Ventura entered the season running the thinnest White Sox team in years, so he would need to gain advantages elsewhere – or, at the very least, stop with all the surrendering.
Margalus does a great evaluation of how Ventura compared to Guillen through the first half the season. Some of these efficiencies undoubtedly contribute to why the Sox are in first place, but a half a season is nothing more than a small sample size for now.