After seeing may of the Cubs bats go cold in the playoffs, I started wondering whether there are any statistics that measure consistency in performance. It sure seems that players like Rizzo and Bryant have had huge up and down swings throughout the season. I would imagine that most players follow a similar pattern, but are there any stats that would measure the variance in a player's performance over the course of seasons? In other words, can we identify a guy whose rate stats were very stable over the entire season versus someone who fluctuated up and down to arrive at the same result? I don't know how much value, if any, there would be in such a measurement, since there are many other factors like the park, pitcher, weather, etc. that could impact results. I am really just curious whether anything exists, or has been attempted, to measure hitter consistency.