First of all, let me clarify (in case there is any misunderstanding) that the outcome of 1 run games is not solely luck or randomness. Skill does play some part in it, but in 1 run games (and even 2 run games), randomness trumps skill.
Two things to consider, which again are fact, not just my opinion:
1. You can tell a lot more about the true talent level of the team by looking at its record in 4+ run games than you can by looking at its record in 1 or 2 run games. In other words, records in 4+ run games correlate a lot stronger to overall season record than do the records in 1 or 2 run games.
2. Team records in 1 run games will regress to .500. Or in other words, maintaining a good record in 1 run games is not a repeatable skill.
Exhibit A - The 2012 Orioles were 29-9 in one run games. Many of the "good teams know how to win the close games" crowd credited Showalter's genius managing and the Os incredible BP for the record.
The 2013 Orioles, which was largely the same team and certainly the same manager, had a 20-31 record in one run games. Did the genius Showalter suddenly forget how to manage? Did the vaunted BP forget how to pitch? Did the great Orioles team suddenly forget how to win the close games?
Or perhaps, those records had more to do with randomness than anything else.