Update accuracy calculation for latest Gen 7 research (#7806)

data/abilities.ts

@@ -487,11 +487,11 @@ export const Abilities: {[abilityid: string]: AbilityData} = {
 		num: 172,
 	},
 	compoundeyes: {
-		onSourceModifyAccuracyPriority: 9,
+		onSourceModifyAccuracyPriority: -1,
 		onSourceModifyAccuracy(accuracy) {
 			if (typeof accuracy !== 'number') return;
 			this.debug('compoundeyes - enhancing accuracy');
-			return accuracy * 1.3;
+			return this.chainModify([0x14CD, 0x1000]);
 		},
 		name: "Compound Eyes",
 		rating: 3,
@@ -1430,10 +1430,10 @@ export const Abilities: {[abilityid: string]: AbilityData} = {
 		onModifyAtk(atk) {
 			return this.modify(atk, 1.5);
 		},
-		onSourceModifyAccuracyPriority: 7,
+		onSourceModifyAccuracyPriority: -1,
 		onSourceModifyAccuracy(accuracy, target, source, move) {
 			if (move.category === 'Physical' && typeof accuracy === 'number') {
-				return accuracy * 0.8;
+				return this.chainModify([0x0CCD, 0x1000]);
 			}
 		},
 		name: "Hustle",
@@ -3076,12 +3076,12 @@ export const Abilities: {[abilityid: string]: AbilityData} = {
 		onImmunity(type, pokemon) {
 			if (type === 'sandstorm') return false;
 		},
-		onModifyAccuracyPriority: 8,
+		onModifyAccuracyPriority: -1,
 		onModifyAccuracy(accuracy) {
 			if (typeof accuracy !== 'number') return;
 			if (this.field.isWeather('sandstorm')) {
 				this.debug('Sand Veil - decreasing accuracy');
-				return accuracy * 0.8;
+				return this.chainModify([0x0CCD, 0x1000]);
 			}
 		},
 		name: "Sand Veil",
@@ -3400,12 +3400,12 @@ export const Abilities: {[abilityid: string]: AbilityData} = {
 		onImmunity(type, pokemon) {
 			if (type === 'hail') return false;
 		},
-		onModifyAccuracyPriority: 8,
+		onModifyAccuracyPriority: -1,
 		onModifyAccuracy(accuracy) {
 			if (typeof accuracy !== 'number') return;
 			if (this.field.isWeather('hail')) {
 				this.debug('Snow Cloak - decreasing accuracy');
-				return accuracy * 0.8;
+				return this.chainModify([0x0CCD, 0x1000]);
 			}
 		},
 		name: "Snow Cloak",
@@ -3799,12 +3799,12 @@ export const Abilities: {[abilityid: string]: AbilityData} = {
 		num: 28,
 	},
 	tangledfeet: {
-		onModifyAccuracyPriority: 6,
+		onModifyAccuracyPriority: -1,
 		onModifyAccuracy(accuracy, target) {
 			if (typeof accuracy !== 'number') return;
 			if (target?.volatiles['confusion']) {
 				this.debug('Tangled Feet - decreasing accuracy');
-				return accuracy * 0.5;
+				return this.chainModify(0.5);
 			}
 		},
 		name: "Tangled Feet",
@@ -4080,9 +4080,10 @@ export const Abilities: {[abilityid: string]: AbilityData} = {
 		num: 260,
 	},
 	victorystar: {
-		onAllyModifyMove(move) {
-			if (typeof move.accuracy === 'number') {
-				move.accuracy *= 1.1;
+		onAnyModifyAccuracyPriority: -1,
+		onAnyModifyAccuracy(accuracy, target, source) {
+			if (source.side === this.effectData.target.side && typeof accuracy === 'number') {
+				return this.chainModify([0x119A, 0x1000]);
 			}
 		},
 		name: "Victory Star",

data/items.ts

@@ -562,11 +562,11 @@ export const Items: {[itemid: string]: ItemData} = {
 		fling: {
 			basePower: 10,
 		},
-		onModifyAccuracyPriority: 5,
+		onModifyAccuracyPriority: -2,
 		onModifyAccuracy(accuracy) {
 			if (typeof accuracy !== 'number') return;
 			this.debug('brightpowder - decreasing accuracy');
-			return accuracy * 0.9;
+			return this.chainModify([0x0F1C, 0x1000]);
 		},
 		num: 213,
 		gen: 2,
@@ -2794,11 +2794,11 @@ export const Items: {[itemid: string]: ItemData} = {
 		fling: {
 			basePower: 10,
 		},
-		onModifyAccuracyPriority: 5,
+		onModifyAccuracyPriority: -2,
 		onModifyAccuracy(accuracy) {
 			if (typeof accuracy !== 'number') return;
 			this.debug('lax incense - decreasing accuracy');
-			return accuracy * 0.9;
+			return this.chainModify([0x0F1C, 0x1000]);
 		},
 		num: 255,
 		gen: 3,
@@ -3463,12 +3463,13 @@ export const Items: {[itemid: string]: ItemData} = {
 		},
 		condition: {
 			duration: 2,
-			onSourceModifyAccuracyPriority: 3,
-			onSourceModifyAccuracy(accuracy, target, source) {
-				this.add('-enditem', source, 'Micle Berry');
-				source.removeVolatile('micleberry');
-				if (typeof accuracy === 'number') {
-					return accuracy * 1.2;
+			onSourceAccuracy(accuracy, target, source, move) {
+				if (!move.ohko) {
+					this.add('-enditem', source, 'Micle Berry');
+					source.removeVolatile('micleberry');
+					if (typeof accuracy === 'number') {
+						return this.chainModify([0x1333, 0x1000]);
+					}
 				}
 			},
 		},
@@ -6737,10 +6738,10 @@ export const Items: {[itemid: string]: ItemData} = {
 		fling: {
 			basePower: 10,
 		},
-		onSourceModifyAccuracyPriority: 4,
+		onSourceModifyAccuracyPriority: -2,
 		onSourceModifyAccuracy(accuracy) {
 			if (typeof accuracy === 'number') {
-				return accuracy * 1.1;
+				return this.chainModify([0x1199, 0x1000]);
 			}
 		},
 		num: 265,
@@ -6837,11 +6838,11 @@ export const Items: {[itemid: string]: ItemData} = {
 		fling: {
 			basePower: 10,
 		},
-		onSourceModifyAccuracyPriority: 4,
+		onSourceModifyAccuracyPriority: -2,
 		onSourceModifyAccuracy(accuracy, target) {
 			if (typeof accuracy === 'number' && !this.queue.willMove(target)) {
 				this.debug('Zoom Lens boosting accuracy');
-				return accuracy * 1.2;
+				return this.chainModify([0x1333, 0x1000]);
 			}
 		},
 		num: 276,

data/mods/gen4/abilities.ts

@@ -44,6 +44,15 @@ export const Abilities: {[k: string]: ModdedAbilityData} = {
 		},
 		onAfterMoveSecondary() {},
 	},
+	compoundeyes: {
+		onSourceModifyAccuracyPriority: 9,
+		onSourceModifyAccuracy(accuracy) {
+			if (typeof accuracy !== 'number') return;
+			this.debug('compoundeyes - enhancing accuracy');
+			return accuracy * 1.3;
+		},
+		inherit: true,
+	},
 	cutecharm: {
 		inherit: true,
 		onDamagingHit(damage, target, source, move) {
@@ -147,6 +156,15 @@ export const Abilities: {[k: string]: ModdedAbilityData} = {
 			this.add('-activate', pokemon, 'ability: Forewarn', warnMove);
 		},
 	},
+	hustle: {
+		inherit: true,
+		onSourceModifyAccuracyPriority: 7,
+		onSourceModifyAccuracy(accuracy, target, source, move) {
+			if (move.category === 'Physical' && typeof accuracy === 'number') {
+				return accuracy * 0.8;
+			}
+		},
+	},
 	insomnia: {
 		inherit: true,
 		rating: 2.5,
@@ -313,6 +331,17 @@ export const Abilities: {[k: string]: ModdedAbilityData} = {
 			}
 		},
 	},
+	sandveil: {
+		inherit: true,
+		onModifyAccuracyPriority: 8,
+		onModifyAccuracy(accuracy) {
+			if (typeof accuracy !== 'number') return;
+			if (this.field.isWeather('sandstorm')) {
+				this.debug('Sand Veil - decreasing accuracy');
+				return accuracy * 0.8;
+			}
+		},
+	},
 	serenegrace: {
 		inherit: true,
 		onModifyMove(move) {
@@ -335,8 +364,16 @@ export const Abilities: {[k: string]: ModdedAbilityData} = {
 		rating: 4,
 		num: 86,
 	},
-	soundproof: {
+	snowcloak: {
 		inherit: true,
+		onModifyAccuracyPriority: 8,
+		onModifyAccuracy(accuracy) {
+			if (typeof accuracy !== 'number') return;
+			if (this.field.isWeather('hail')) {
+				this.debug('Snow Cloak - decreasing accuracy');
+				return accuracy * 0.8;
+			}
+		},
 	},
 	static: {
 		inherit: true,
@@ -396,6 +433,17 @@ export const Abilities: {[k: string]: ModdedAbilityData} = {
 			source.trySetStatus(id, target);
 		},
 	},
+	tangledfeet: {
+		inherit: true,
+		onModifyAccuracyPriority: 6,
+		onModifyAccuracy(accuracy, target) {
+			if (typeof accuracy !== 'number') return;
+			if (target?.volatiles['confusion']) {
+				this.debug('Tangled Feet - decreasing accuracy');
+				return accuracy * 0.5;
+			}
+		},
+	},
 	thickfat: {
 		onSourceBasePowerPriority: 1,
 		onSourceBasePower(basePower, attacker, defender, move) {

data/mods/gen4/items.ts

@@ -16,6 +16,15 @@ export const Items: {[k: string]: ModdedItemData} = {
 			}
 		},
 	},
+	brightpowder: {
+		inherit: true,
+		onModifyAccuracyPriority: 5,
+		onModifyAccuracy(accuracy) {
+			if (typeof accuracy !== 'number') return;
+			this.debug('brightpowder - decreasing accuracy');
+			return accuracy * 0.9;
+		},
+	},
 	choiceband: {
 		inherit: true,
 		onStart() { },
@@ -139,6 +148,15 @@ export const Items: {[k: string]: ModdedItemData} = {
 			}
 		},
 	},
+	laxincense: {
+		inherit: true,
+		onModifyAccuracyPriority: 5,
+		onModifyAccuracy(accuracy) {
+			if (typeof accuracy !== 'number') return;
+			this.debug('lax incense - decreasing accuracy');
+			return accuracy * 0.9;
+		},
+	},
 	lifeorb: {
 		inherit: true,
 		onModifyDamage() {},
@@ -235,6 +253,20 @@ export const Items: {[k: string]: ModdedItemData} = {
 			},
 		},
 	},
+	micleberry: {
+		inherit: true,
+		condition: {
+			duration: 2,
+			onSourceModifyAccuracyPriority: 3,
+			onSourceModifyAccuracy(accuracy, target, source) {
+				this.add('-enditem', source, 'Micle Berry');
+				source.removeVolatile('micleberry');
+				if (typeof accuracy === 'number') {
+					return accuracy * 1.2;
+				}
+			},
+		},
+	},
 	razorfang: {
 		inherit: true,
 		onModifyMove(move) {
@@ -266,4 +298,23 @@ export const Items: {[k: string]: ModdedItemData} = {
 			}
 		},
 	},
+	widelens: {
+		inherit: true,
+		onSourceModifyAccuracyPriority: 4,
+		onSourceModifyAccuracy(accuracy) {
+			if (typeof accuracy === 'number') {
+				return accuracy * 1.1;
+			}
+		},
+	},
+	zoomlens: {
+		inherit: true,
+		onSourceModifyAccuracyPriority: 4,
+		onSourceModifyAccuracy(accuracy, target) {
+			if (typeof accuracy === 'number' && !this.queue.willMove(target)) {
+				this.debug('Zoom Lens boosting accuracy');
+				return accuracy * 1.2;
+			}
+		},
+	},
 };

data/mods/gen4/scripts.ts

@@ -97,6 +97,63 @@ export const Scripts: ModdedBattleScriptsData = {
 		}
 		return hitResults;
 	},
+	hitStepAccuracy(targets, pokemon, move) {
+		const hitResults = [];
+		for (const [i, target] of targets.entries()) {
+			this.activeTarget = target;
+			// calculate true accuracy
+			let accuracy = move.accuracy;
+			if (move.ohko) { // bypasses accuracy modifiers
+				if (!target.isSemiInvulnerable()) {
+					if (pokemon.level < target.level) {
+						this.add('-immune', target, '[ohko]');
+						hitResults[i] = false;
+						continue;
+					}
+					accuracy = 30 + pokemon.level - target.level;
+				}
+			} else {
+				const boostTable = [1, 4 / 3, 5 / 3, 2, 7 / 3, 8 / 3, 3];
+
+				let boosts;
+				let boost!: number;
+				if (accuracy !== true) {
+					if (!move.ignoreAccuracy) {
+						boosts = this.runEvent('ModifyBoost', pokemon, null, null, {...pokemon.boosts});
+						boost = this.clampIntRange(boosts['accuracy'], -6, 6);
+						if (boost > 0) {
+							accuracy *= boostTable[boost];
+						} else {
+							accuracy /= boostTable[-boost];
+						}
+					}
+					if (!move.ignoreEvasion) {
+						boosts = this.runEvent('ModifyBoost', target, null, null, {...target.boosts});
+						boost = this.clampIntRange(boosts['evasion'], -6, 6);
+						if (boost > 0) {
+							accuracy /= boostTable[boost];
+						} else if (boost < 0) {
+							accuracy *= boostTable[-boost];
+						}
+					}
+				}
+				accuracy = this.runEvent('ModifyAccuracy', target, pokemon, move, accuracy);
+			}
+			if (move.alwaysHit) {
+				accuracy = true; // bypasses ohko accuracy modifiers
+			} else {
+				accuracy = this.runEvent('Accuracy', target, pokemon, move, accuracy);
+			}
+			if (accuracy !== true && !this.randomChance(accuracy, 100)) {
+				if (!move.spreadHit) this.attrLastMove('[miss]');
+				this.add('-miss', pokemon, target);
+				hitResults[i] = false;
+				continue;
+			}
+			hitResults[i] = true;
+		}
+		return hitResults;
+	},
 
 	calcRecoilDamage(damageDealt, move) {
 		return this.clampIntRange(Math.floor(damageDealt * move.recoil![0] / move.recoil![1]), 1);

data/moves.ts

@@ -7279,7 +7279,7 @@ export const Moves: {[moveid: string]: MoveData} = {
 			},
 			onModifyAccuracy(accuracy) {
 				if (typeof accuracy !== 'number') return;
-				return accuracy * 5 / 3;
+				return this.chainModify([0x1AB8, 0x1000]);
 			},
 			onDisableMove(pokemon) {
 				for (const moveSlot of pokemon.moveSlots) {

data/scripts.ts

@@ -452,31 +452,23 @@ export const Scripts: BattleScriptsData = {
 					}
 				}
 			} else {
-				const boostTable = [1, 4 / 3, 5 / 3, 2, 7 / 3, 8 / 3, 3];
-
-				let boosts;
-				let boost!: number;
+				accuracy = this.runEvent('ModifyAccuracy', target, pokemon, move, accuracy);
 				if (accuracy !== true) {
+					let boost = 0;
 					if (!move.ignoreAccuracy) {
-						boosts = this.runEvent('ModifyBoost', pokemon, null, null, {...pokemon.boosts});
+						const boosts = this.runEvent('ModifyBoost', pokemon, null, null, {...pokemon.boosts});
 						boost = this.clampIntRange(boosts['accuracy'], -6, 6);
-						if (boost > 0) {
-							accuracy *= boostTable[boost];
-						} else {
-							accuracy /= boostTable[-boost];
-						}
 					}
 					if (!move.ignoreEvasion) {
-						boosts = this.runEvent('ModifyBoost', target, null, null, {...target.boosts});
-						boost = this.clampIntRange(boosts['evasion'], -6, 6);
-						if (boost > 0) {
-							accuracy /= boostTable[boost];
-						} else if (boost < 0) {
-							accuracy *= boostTable[-boost];
-						}
+						const boosts = this.runEvent('ModifyBoost', target, null, null, {...target.boosts});
+						boost = this.clampIntRange(boost - boosts['evasion'], -6, 6);
+					}
+					if (boost > 0) {
+						accuracy = this.trunc(accuracy * (3 + boost) / 3);
+					} else if (boost < 0) {
+						accuracy = this.trunc(accuracy * 3 / (3 - boost));
 					}
 				}
-				accuracy = this.runEvent('ModifyAccuracy', target, pokemon, move, accuracy);
 			}
 			if (move.alwaysHit || (move.id === 'toxic' && this.gen >= 6 && pokemon.hasType('Poison'))) {
 				accuracy = true; // bypasses ohko accuracy modifiers

sim/dex-conditions.ts

@@ -524,6 +524,7 @@ export interface EventMethods {
 	onAfterMoveSelfPriority?: number;
 	onAnyBasePowerPriority?: number;
 	onAnyInvulnerabilityPriority?: number;
+	onAnyModifyAccuracyPriority?: number;
 	onAnyFaintPriority?: number;
 	onAnyPrepareHitPriority?: number;
 	onAllyBasePowerPriority?: number;

test/sim/misc/accuracy.js

@@ -0,0 +1,86 @@
+'use strict';
+
+const assert = require('./../../assert');
+const common = require('./../../common');
+
+let battle;
+
+describe("Accuracy", function () {
+	afterEach(function () {
+		battle.destroy();
+	});
+
+	it(`should round half down when applying a modifier`, function () {
+		battle = common.createBattle([
+			[{species: 'Butterfree', ability: 'compoundeyes', moves: ['sleeppowder']}],
+			[{species: 'Beldum', moves: ['poltergeist']}],
+		]);
+
+		battle.onEvent('Accuracy', battle.format, function (accuracy) {
+			assert.equal(accuracy, 98, 'CompoundEyes Sleep Powder should be 98% accurate');
+		});
+
+		battle.makeChoices();
+
+		battle = common.createBattle([
+			[{species: 'Butterfree', ability: 'victorystar', moves: ['fireblast']}],
+			[{species: 'Regirock', moves: ['sleeptalk']}],
+		]);
+
+		battle.onEvent('Accuracy', battle.format, function (accuracy) {
+			assert.equal(accuracy, 94, 'Victory Star Fire Blast should be 94% accurate');
+		});
+
+		battle.makeChoices();
+
+		battle = common.createBattle([
+			[{species: 'Butterfree', item: 'widelens', moves: ['fireblast']}],
+			[{species: 'Regirock', moves: ['sleeptalk']}],
+		]);
+
+		battle.onEvent('Accuracy', battle.format, function (accuracy) {
+			assert.equal(accuracy, 93, 'Wide Lens Fire Blast should be 93% accurate');
+		});
+
+		battle.makeChoices();
+	});
+
+	it(`should chain modifiers in order of the Pokemon's raw speed`, function () {
+		battle = common.createBattle({gameType: 'doubles'}, [[
+			{species: 'Mewtwo', ability: 'victorystar', moves: ['gravity', 'sleeptalk', 'sandattack']},
+			{species: 'Charizard', ability: 'compoundeyes', moves: ['sleeptalk', 'fireblast']},
+		], [
+			{species: 'Bonsly', ability: 'tangledfeet', moves: ['doubleteam', 'sleeptalk']},
+			{species: 'Pyukumuku', ability: 'noguard', moves: ['confuseray', 'sandattack', 'sleeptalk']},
+		]]);
+
+		battle.makeChoices('move sandattack -2, move sleeptalk', 'move doubleteam, move sandattack 2');
+		battle.makeChoices('auto', 'move sleeptalk, move confuseray -1');
+
+		battle.onEvent('Accuracy', battle.format, function (accuracy, target, source, move) {
+			if (move.id !== 'fireblast') return;
+			assert.equal(accuracy, 51);
+		});
+
+		battle.makeChoices('move gravity, move fire blast 1', 'move sleeptalk, move sleeptalk');
+
+		// Changing the Pokemon's Speeds around changes the chaining order, which affects the result
+		battle = common.createBattle({gameType: 'doubles'}, [[
+			{species: 'Bonsly', ability: 'victorystar', moves: ['gravity', 'sleeptalk', 'sandattack']},
+			{species: 'Charizard', ability: 'compoundeyes', moves: ['sleeptalk', 'fireblast']},
+		], [
+			{species: 'Mewtwo', ability: 'tangledfeet', moves: ['doubleteam', 'sleeptalk']},
+			{species: 'Pyukumuku', ability: 'noguard', moves: ['confuseray', 'sandattack', 'sleeptalk']},
+		]]);
+
+		battle.makeChoices('move sandattack -2, move sleeptalk', 'move doubleteam, move sandattack 2');
+		battle.makeChoices('auto', 'move sleeptalk, move confuseray -1');
+
+		battle.onEvent('Accuracy', battle.format, function (accuracy, target, source, move) {
+			if (move.id !== 'fireblast') return;
+			assert.equal(accuracy, 50);
+		});
+
+		battle.makeChoices('move gravity, move fire blast 1', 'move sleeptalk, move sleeptalk');
+	});
+});