For a change, let’s not look at a blunder, but at a small mistake.
Over the board, I played 17/11 13/8, just bring the checkers home that are furthest away.
This was a (minor) mistake, losing 0.03 points of equity.
Why? If you look at the correct play 17/6, you can see that it avoids gammon for 44, 55, 66, while my play only avoids gammon for 55 and 66. A small difference, but easy to see.
Incidentally I rolled 33, and just not avoided a gammon.