When eating a bowl of chips at a pub, or a packet of fries at a fast-food outlet, I like to empty 2 or 3 ketchup sachets onto a limited area of chippage. Normally most of the ketchup falls onto one chip, but there is always a fallout area covering 3 or 4 chips. The central chip in the catchment area will normally become so soggy that when I do eat it, after consuming all other available non-dead chips*, it's difficult to taste anything other than ketchup.
Anyway, I like to refer to this as the "sacrificial chip". Please help me to push this phrase into common use. Personally, I like the sacrificial chip, indeed consider it the pinnacle of the bowl-of-chips eating experience, but I have at least one friend who dislikes sacrificing chips so much that she will "ketchup" (that's a verb) each chip individually, directly from the sachet.
*Dead chips are the chips that are either too crispy to chew, or chips that simply look odd, presumably due to inconsistencies in the McKentuckyBurger "french fry" manufacturing process.