based on Damage Resistance but it subtracts from Control Points instead of Hit Points lost from GURPS Martial Arts: Technical Grappling attacks.
It may also be applicable in subtracting from the Control Point "damage" that a successful "Break Free" attack does to your grapple, based on text in the "handholds" ("rugged loose sleeves, reinforced collars and stitching, and load-bearing straps on your foe’s clothing and armor") paragraph of TG 7:
- This also gives you Control Resistance equal to the same amount, but only against his attempts to break free from your grapple.
The example given:
- When his foe tries to break free, Dave will subtract 2 CP (0.1x15) from successful attempts.
1.5 becoming 2 is based on:
- If successful, increase CP rolled by 0.1 x(Trained ST), rounded normally
Pg 15:
- Some weapons have Control Resistance (p. 27), making them more difficult to escape or break free from. Subtract Control Resistance from any rolls to remove CP from the grapple.
pg 28:
- A Binding attack possesses both DR and Control Resistance (p. 27) equal to 1/3 its level (round down).
Pg 31:
- Each attack inflicts CP based on your skill, and has Control Resistance (p. 27) equal to the training bonus you would receive according to the fast progression.
Pg 32:
- With Knot-Tying at DX+4, his knots have Control
Resistance 3.
31-32 is another example where this is subtracted from CP rolled for Break Free.
29 is confusing:
- Each level of Stretching adds Control Resistance 1 against wrenches and locks
Wrenches and locks are attacks made after establishing control, not CP applicators themselves.
Slippery higher on the page is also helpful for understanding applications, especially with the Affects Others Only enhancement.
What seems unclear about sweat and oil is while it is clear that it should make it harder to get CP applied on you, it is unclear why it should make it harder to break free from you (be penalizing the CP rolled against a secured grapple)
Pg 27 defines:
- Subtract Control Resistance from any CP inflicted by a grappling attack or defense
"Break Free" is a "Grappling Attack", so it would be penalized too. The idea appears to be that since break free involves trying to pull their hand off you, if you can't get a good grip on that hand, it would be hard to do that.
Where it doesn't make sense however is something like Bucking Bronco which doesn't involve gripping them at all.
Pg 27 also:
- If you penetrate your foe’s DR, he loses any Control Resistance (below) that he may have had from being sweaty or oiled up (p. 7), Slippery (p. 29), etc. – you’re not gripping him anymore, you have your claws buried in his flesh!
This is likely intended to be location-based, ie CR is only lost in respect to that penetrated location. If claws were sunk into one arm but none were sunk into the other, the CP should still be intact on that other arm.