Far superior team. Far superior starting pitcher and a stronger bullpen.The Padres check the boxes here. That's why they are such a strong favorite. I have to believe they are going to win this game by at least two runs so I'm going to lay them on the run line to avoid the heavy juice. 
The Diamondbacks appear to have made a foolish investment in Madison Bumgarner signing him to a five-year, $85 million contract. Bumgarner still is just 31, but he has a lot of wear-and-tear that showed itself last season when he went 1-4 with a 6.48 ERA in nine starts. Bumgarner doesn't have a good history at Petco Park either with a 5-9 career record and 4.38 ERA. 
How bad is Arizona's bullpen? Joakim Soria is the closer. So Bumgarner isn't going to get any relief help. 
The Padres posted their highest winning percentage last season going 37-23. They look even better this season. Yu Darvish is one reason for this. He finished No. 2 in the Cy Young Award balloting with an 8-3 record and 2.01 ERA in 12 starts in 2020. He has a 2.93 lifetime ERA versus the Diamondbacks in five starts with 53 strikeouts in 30 2/3 innings.