[sonneti]

I think if you bet big on the river you are getting called. What hand range is calling 400 on the turn and not calling a non spade river?

I don't want to give up value by letting weaker hands check behind, also the only way a river check will be profitable is if the villan donk bluffs his chips in on a wiffed spade draw. Which given the action before and your read I don't think is very likely.