In 2015, he played in 140 games and he had 101 runs with 169 hits, 34 doubles, 16 home runs, 72 RBI, 28 stolen bases, a .307/.361/.477 offensive slash line, and an OPS+ of 125. He was an All-Star for the American League and he also came in third in MVP voting in the American League behind Los Angeles Angels outfielder Mike Trout and Toronto Blue Jays third baseman Josh Donaldson, who won the award in 2015.
Last season, he played in 155 games with 86 runs, 175 hits, 27 doubles, 15 home runs, 49 RBI, 26 stolen bases, a .300/.363/.440 slashline, and a 112 OPS+.
You can obviously say that Cain is not as good as Blackmon in the power department but he is still somebody who gets on base a lot of the time. If he could hit in the top one or two spots in the lineup and move Blackmon to a more traditional power spot in the lineup or even put him in the sixth or seventh spot to get on for weaker hitters to advance Cain on the bases, runs will be more plentiful. However, discussing what the Rockies 2018 lineup (with or without Cain or other free agents) is something we can discuss for a later date.
Also, if the Rockies were to get Lorenzo Cain, he would be an elite defender.