pokecrystal-board/engine/battle_anims/getpokeballwobble.asm

GetPokeBallWobble: ; f971 (3:7971)
; Returns whether a Poke Ball will wobble in the catch animation.
; Whether a Pokemon is caught is determined beforehand.

	push de

	ld a, [rSVBK]
	ld d, a
	push de

	ld a, BANK(wBuffer2)
	ld [rSVBK], a

	ld a, [wBuffer2]
	inc a
	ld [wBuffer2], a

; Wobble up to 3 times.
	cp 3 + 1
	jr z, .finished

	ld a, [wWildMon]
	and a
	ld c, 0 ; next
	jr nz, .done

	ld hl, .WobbleProbabilities
	ld a, [wBuffer1]
	ld b, a
.loop
	ld a, [hli]
	cp b
	jr nc, .checkwobble
	inc hl
	jr .loop

.checkwobble
	ld b, [hl]
	call Random
	cp b
	ld c, 0 ; next
	jr c, .done
	ld c, 2 ; escaped
	jr .done

.finished
	ld a, [wWildMon]
	and a
	ld c, 1 ; caught
	jr nz, .done
	ld c, 2 ; escaped

.done
	pop de
	ld e, a
	ld a, d
	ld [rSVBK], a
	ld a, e
	pop de
	ret

.WobbleProbabilities: ; f9ba
; catch rate, chance of wobbling / 255
; nLeft/255 = (nRight/255) ** 4
	db   1,  63
	db   2,  75
	db   3,  84
	db   4,  90
	db   5,  95
	db   7, 103
	db  10, 113
	db  15, 126
	db  20, 134
	db  30, 149
	db  40, 160
	db  50, 169
	db  60, 177
	db  80, 191
	db 100, 201
	db 120, 211
	db 140, 220
	db 160, 227
	db 180, 234
	db 200, 240
	db 220, 246
	db 240, 251
	db 254, 253
	db 255, 255