1. A team's record in one run games will eventually regress to .500.
That's just not true.
If someone flips a coin head 50 times in a row, it does not mean that by 1,000 flips, they will be closer to 500 heads and 500 tails than had they flipped 25 heads and 25 tails over the first 50 flips.
If a team starts out winning way more one-run games than the norm, chances are they will begin to win their norm for the remainder of the season- not make up for it by losing more one-run games than statistically probable.
If a .500 team wins 10 more games by 0ne run at the halfway point of a season, they'd probably be projected to end the season with 10 more wins, as statistically, they'd be projected to go .500 in those games over the second half.
15-5 first half
10-10 second half
25-15 final numbers (not 20-20). Now, 25-15 is closer to their norm than 15-5, so in a way they are progressing towards the norm, but they should never really reach the actual norm after starting off with a massive anomaly.
Seattle is still 31-16 in one-run games. They will not be at .500 in these games by season's end.