You keep using this term repeatable skill, and I have to say that I don’t know the significance of that term in a sport that is as dynamic as baseball where your opponent is countering your every move. Winning 1 & 2 run games is not a repeatable skill, but you are saying that winning blowout games is a repeatable skill? Is that what you are saying?
As for the Baltimore example, while I agree that the skewed records in 1 run games had something to do with good and bad fortune, the fact that the 2012 team won more than it lost was in greater part due to the fact that it was a better team than the 2013 team. It could also have to do with the fact that the 1 run games in 2013 were played against better teams. Just because the personnel on both teams were very similar doesn’t attribute the deviation to luck. Players perform differently from play to play, game to game, and so on. A player can strike out on a pitch and on the next pitch hit the same pitch in the same location for a HR. He doesn’t come back to the dugout talking about the randomness of the outcome. He knows what he did right when he hit the HR and what he did wrong when he swung and missed. The variation was in his performance. It wasn’t randomness at work. The Oriole 2012 team performed better than the 2013 team.
Can there be a more repeatable skill than rolling a bowling ball? The ball is the same on every throw. The lane stays exactly the same and the pins are always positioned in the same spots. The sport is played indoors so there is no wind or other weather related variation. Yet, even a champion bowler like Mookie Betts who has rolled a high number of 300 games doesn’t come close to rolling 300 games every time. Is it randomness? No. The variation is in his performance. He knows exactly where he needs to put the ball to get a strike. The problem is that if he is not precise he will leave the 7 pin or the 10 pin or some other pin. Those pins didn’t randomly avoid the collision of the other pins. He just missed his spot. Now, let’s take a sport like baseball that is not static like bowling. There is an opponent countering your every move, umpires with varying strike zones, weather elements and fields of different dimensions come into the dynamics of the game. Those dynamics are not elements of randomness, but they do affect performance. In the end, it is a game of applied skill between 2 the most highly skilled performers in the world and the outcome of those contests is rarely random.