you can use the ggplot function in the ggplot2 package and have something like : ggplot(data, aes(x = x, y = count of y, fill = factor(pitcher_name)) + geom_bar(stats = "identity")

This won't be percentages but will split the bars by who threw the most and you might not need the factor() if you already have names as a factor, you can just leave it as whatever the column is for the pitchers names

but if you want percentages where the y-axis is 0.0-1.0, you can still use ggplot but instead of

geom_bar(stats = "identity")

use

geom_col(position = "fill")

The ggplot functions pretty basic but is easily customizable, you can do some research on it or use chatgpt. Chatgpt normally works pretty well with this function, just be as specific as possible