Say you have a character with Reflexes B4 — pretty standard for many kinds of PCs and NPCs in Burning Wheel.
That character is likely to eventually face someone with Reflexes B5 or B6, maybe even B7. The higher-Reflex character gains more actions in Fight — actions which they can execute without opposition.
What should the lower-Reflex fighter do against faster enemies? Which combat maneuvers and tricks are best for shoring up a deficit of actions per exchange?
There's basically two guiding principles you want to do - stack them up with Ob/Dice penalties, and hit them first, hard. Wounds that inflict dice penalties will reduce their Reflexes and force them to make a Steel test and possibly get them Hesitating.
You stack penalties by: having a reach advantage (longer, or shorter), using Lock, knocking them down with a Push, Charge, or Throw. All of this makes you harder to hit even if they have extra actions. Armor also helps - if you can fully soak a few hits, you can focus on offense (Aggressive Stance) instead.
A very successful Block can cost them a whole extra action, and leave them open for a followup move.
This of course, goes on top of the usual caveat of fighting dirty - shoot them at a distance, ambush them, throw a net on them, throw lye in their eyes, etc. If your character knows they're going up against someone who outclasses them, set up things in your favor.
