A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
Cornering Maneuver Battle: If no Terrain is in play: Target an enemy Personality with lower base Force than each of your Personalities at the current battlefield. Search your Fate deck for a Terrain. Show it. You may take an additional Battle action to play it; if you do not, discard it.
Do you only check the base force of the enemy target or our own base force as well?
Cornering Maneuver Battle: If no Terrain is in play: Target an enemy Personality with lower base Force than each of your Personalities at the current battlefield. Search your Fate deck for a Terrain. Show it. You may take an additional Battle action to play it; if you do not, discard it.
Do you only check the base force of the enemy target or our own base force as well?
The only stat referenced is "Base Force." You check the Base Force for each card in question - not the Current Force.