This bet is only 1.884 on Pinnacle, providing us with a decent +EV of 5.6%. On top of this, this under-line seems to be dropping across many other Asian bookmakers - many sitting around 1.65-1.70. The referee averages 3.61 cards per game in the Bundesliga, but it is worth noting that Bayern are major favourites (1.062 to win) which often results in less cards.