Measured tafl game haphazardness.

Tafl variant	Game balance	Counted games	Game haphazardness
Historical Hnefatafl 11x11	+1.06	446	32%
Simple Hnefatafl 11x11 (aka Welsh Tawlbwrdd)	-1.19	56	32%
Historical Hnefatafl 9x9 (aka Saami Tablut)	+1.21	89	36%
Copenhagen Hnefatafl 11x11	+1.31	8033	38%
Market Hnefatafl 9x9	-1.15	152	39%
Frisian Dablo0 11x9	+1.14	67	33%
Saami Daabloe 11x9	+1.18	111	40%
Frisian Dablo 11x9	+1.09	144	43%
Frisian Dablo2 11x9	1.00	14	86%
Saami Sáhkku 3x15 (Kåfjord)	-1.14	183	61%
Daldøs 3x14	1.00	340	65%
Daldøs 3x12	+1.09	293	81%
Daldøs 3x16	+1.08	231	87%

The game haphazardness is calculated as:
(number of games where, after adjusting for game balance, a lower rated player wins against a higher rated player) divided by (number of counted games) * 2
Draws are counted as half wins.
Only games between players of adjusted ratings separated by at least 150, are counted.

Imagine a completely uncontrollable game, where the outcome is random like throwing a dice. The higher rated player would win half the games and lose half the games, and the game haphazardness would be 100%.
In a completely controllable game, where the higher rated player always wins, the game haphazardness would be 0 %.

A completely random game would seemingly have a game balance of 1. So some game variants can have seemingly good game balances, which are only caused by a random outcome.

Apparently, measured this way, the normal range of haphazardness is up to 50%.