Look at the National League standings and you'll find a surprise leader: the Colorado Rockies. They have the best mark in the NL at 11-4. 
The Rockies may be playing above their heads, but I like them to win here at home against the 6-10 Diamondbacks. 
Colorado is pitching its ace, Jon Gray. Arizona is going with lefty Robbie Ray. The Rockies are 7-0 the past seven times facing a southpaw starter.
Ray is a great strikeout artist, but a mediocre pitcher. He's never been able to harnas his control and it's evident again this season. He has a 9.45 ERA and 1.95 WHIP. He doesn't go deep into games either because he throws so many pitches. 
Ray has a 5.20 career ERA in 17 starts against the Rockies. Current Rockies are batting a combined .328 against him in 214 plate appearances. 
Gray's .694 home winning percentage is second-best in franchise history. 
Arizona has lost 10 of the last 12 times it has been a road 'dog. Colorado has defeated the Diamondbacks six of the past eight times at Coors Field.