[kronckew]

just to mix the batch a bit, the moro kris has a similar construction, (possibly the overall design was already 'locked' from it's indonesian roots by the time it evolved into the moro version?), though used for the cut rather than the thrust, and other moro weapons designed for the cut may or may not have a guard capable of preventing such slippage even though the blade is capable of such.

the grips on most malay/indonesian keris i've seen (tho not all) are more like a push dagger where the grip itself would prevent sliding down the blade even without a guard, also ensuring the weapon cannot slide out of your hand in the opposite direction, and even guardless filipino weapons tend to have a bulbous, or hooked pommel end to prevent that slippage away from the blade even if there is no guard preventing slippage towards it...

scandinavian knives traditionally have a guardless form, a child is given a knife with a guard however, and a sign of his coming of age is when he learns how to use a knife without one even under slippery conditions cleaning game or fish, or the occasional human.

spanish knives, khyber knives, choora, canary knives, gaucho knives all solve the sliding on thrust problem by having an offset grip in line with the spine, with the swell in the blade below the grip preventing the hand and fingers from sliding forward, and most people i've heard discussing those also indicate it offers some ability to deflect an incoming attack and protect the fingers if not the whole forearm...

the decorative notch near the grip (kaudi or cho) of a kukhri has also been described by some as a blood deflector, sword catcher, etc. but the main conclusions about it's purpose and origins are that no one really knows. a kukhri is not really one without it tho. the same goes for the kris, which is incomplete without the ganja/greneng.