Hmm... I thought, of this really simple problem, I saw here... It's kinda the same, simple counting only with Area Scoring - Used in rule sets such as AGAs, Chinese, New Zealands..
(Thanks to the guys at the "straw hut" for the help!)
(;AB[gr]AB[gq]AB[hq]AW[hr]AB[is]AB[ir]AW[fs]AW[gs]AW[fr]AW[fq]LB[hs:A]C[AGA/Chinese/NZ Rules - How big is the difference between white/black playing at A?FORCE]LB[fo:1]LB[go:2]LB[ho:3]LB[io:4]AB[iq]AP[goproblems]
(;W[io]C[Correct. According to the NZ rules set, only territory's counted - Including the territory under the stones. If white takes it, both H1 and H2 are 2 points for him, otherwise it's 2 points for black. The difference, is 4 points. :)FORCERIGHT])
(;W[fo]C[Wrong. According to the NZ rules set, only territory's counted - Including the territory under the stones. If white takes it, both H1 and H2 are 2 points for him, otherwise it's 2 points for black. The difference, is 4 points.FORCE])
(;W[go]C[Wrong. According to the NZ rules set, only territory's counted - Including the territory under the stones. If white takes it, both H1 and H2 are 2 points for him, otherwise it's 2 points for black. The difference, is 4 points.FORCE])
(;W[ho]C[Wrong. According to the NZ rules set, only territory's counted - Including the territory under the stones. If white takes it, both H1 and H2 are 2 points for him, otherwise it's 2 points for black. The difference, is 4 points.FORCE]))