Great insight Risden. No matter how complex your formula gets few if any can accurately measure the impact any given player has on the other players in the lineup. As a Ranger fan I watched the impact Cespedes had on that Oakland team. Before he arrived I almost considered a game against the As to be a vacation day for our pitchers. Time to pad the stats. But not long after he arrived and as the season progressed my thoughts were more along the lines of we better have the bats warmed up.
For those who consider WAR to be the end all for measuring a player's contribution to winning consider this:
only four of the top 12 American League players in terms of WAR and just six of the top 20 even appeared in the postseason. In other words, WAR said they were winners but they failed to contribute to their team winning.
Consider this from baseball-reference.com
Sports Reference sets replacement level at a .320 winning percentage for recent seasons. This means that we expect a team of replacement players to have a .320 win-loss percentage or a 52-110 record.
Now consider World Series champion San Francisco led the NL with a 28.9 WAR. So that means SF should have won 81 games and that would get them a world championship. You should not need a degree from MIT to see something is wrong with that.
The Giants with possibly the best pitching staff in the NL only had a pitching WAR of 5.5, 13th in the NL, barely ahead of Houston who was at 5.4. So the Giants almost had the worst pitching staff in the NL and probably could have swapped out their staff with their AAA affiliate and still won it all. Any stat that tries to tell me those 2 teams pitching staffs were about equal is fundamentally flawed. It makes for interesting conversational material but seriously Houston and SF pitching staffs equal???
Now if I upset anyone too much don't worry. Pitchers and catchers have reported so very soon I will not be nearly as bored or interested in yanking anyone's chain.