Tron doesn't cast red spells and none of our sideboard cards line up well against their ramp-into-big-threats plan (Bramble Wurm and Nyxborn Hydra are green, while Writhing Chrysalis is colorless due to devoid, leaving them untouched by Hydroblast, Steel Sabotage, or the Blasts). Our best plan is simply to race with our efficient tempo clock and use Counterspell to stop their key ramp or threat spells before they hit critical mass. Snaremaster Sprite and Snap are valuable here for tapping down or bouncing their big creatures to buy time. No sideboard changes are worth making since nothing in our board specifically attacks their game plan.