diff --git a/config/formats.ts b/config/formats.ts
index bde10d12e5..ab522b0d30 100644
--- a/config/formats.ts
+++ b/config/formats.ts
@@ -4653,7 +4653,7 @@ export const Formats: import('../sim/dex-formats').FormatList = [
 		mod: 'gen4',
 		gameType: 'doubles',
 		searchShow: false,
-		ruleset: ['Flat Rules', 'Min Team Size = 4', 'Max Team Size = 4', 'Limit Two Restricted'],
+		ruleset: ['Flat Rules', 'Limit Two Restricted'],
 		restricted: ['Restricted Legendary'],
 		banlist: ['Soul Dew'],
 	},
@@ -4662,7 +4662,7 @@ export const Formats: import('../sim/dex-formats').FormatList = [
 		mod: 'gen4pt',
 		gameType: 'doubles',
 		searchShow: false,
-		ruleset: ['Flat Rules', '! Adjust Level Down', 'Max Level = 50', 'Min Team Size = 4', 'Max Team Size = 4'],
+		ruleset: ['Flat Rules', '! Adjust Level Down', 'Max Level = 50'],
 		banlist: ['Tyranitar', 'Rotom', 'Judgment', 'Soul Dew'],
 	},
 	{
diff --git a/data/mods/gen4/rulesets.ts b/data/mods/gen4/rulesets.ts
index 68bdc86226..bbcb4232d2 100644
--- a/data/mods/gen4/rulesets.ts
+++ b/data/mods/gen4/rulesets.ts
@@ -5,7 +5,7 @@ export const Rulesets: import('../../../sim/dex-formats').ModdedFormatDataTable
 	},
 	flatrules: {
 		inherit: true,
-		ruleset: ['Obtainable', 'Species Clause', 'Nickname Clause', 'Item Clause = 1', 'Adjust Level Down = 50', 'Cancel Mod'],
+		ruleset: ['Obtainable', 'Species Clause', 'Nickname Clause', 'Item Clause = 1', 'Adjust Level Down = 50', 'Picked Team Size = Auto', 'Cancel Mod'],
 	},
 	teampreview: {
 		inherit: true,
diff --git a/data/mods/gen8linked/scripts.ts b/data/mods/gen8linked/scripts.ts
index b952d274ee..1c4d7811cf 100644
--- a/data/mods/gen8linked/scripts.ts
+++ b/data/mods/gen8linked/scripts.ts
@@ -65,15 +65,52 @@ export const Scripts: ModdedBattleScriptsData = {
 		case 'start': {
 			for (const side of this.sides) {
 				if (side.pokemonLeft) side.pokemonLeft = side.pokemon.length;
+				this.add('teamsize', side.id, side.pokemon.length);
 			}
 
 			this.add('start');
 
-			if (this.format.onBattleStart) this.format.onBattleStart.call(this);
+			// Change Zacian/Zamazenta into their Crowned formes
+			for (const pokemon of this.getAllPokemon()) {
+				let rawSpecies: Species | null = null;
+				if (pokemon.species.id === 'zacian' && pokemon.item === 'rustedsword') {
+					rawSpecies = this.dex.species.get('Zacian-Crowned');
+				} else if (pokemon.species.id === 'zamazenta' && pokemon.item === 'rustedshield') {
+					rawSpecies = this.dex.species.get('Zamazenta-Crowned');
+				}
+				if (!rawSpecies) continue;
+				const species = pokemon.setSpecies(rawSpecies);
+				if (!species) continue;
+				pokemon.baseSpecies = rawSpecies;
+				pokemon.details = pokemon.getUpdatedDetails();
+				// pokemon.setAbility(species.abilities['0'], null, true);
+				// pokemon.baseAbility = pokemon.ability;
+
+				const behemothMove: { [k: string]: string } = {
+					'Zacian-Crowned': 'behemothblade', 'Zamazenta-Crowned': 'behemothbash',
+				};
+				const ironHead = pokemon.baseMoves.indexOf('ironhead');
+				if (ironHead >= 0) {
+					const move = this.dex.moves.get(behemothMove[rawSpecies.name]);
+					pokemon.baseMoveSlots[ironHead] = {
+						move: move.name,
+						id: move.id,
+						pp: move.noPPBoosts ? move.pp : move.pp * 8 / 5,
+						maxpp: move.noPPBoosts ? move.pp : move.pp * 8 / 5,
+						target: move.target,
+						disabled: false,
+						disabledSource: '',
+						used: false,
+					};
+					pokemon.moveSlots = pokemon.baseMoveSlots.slice();
+				}
+			}
+
+			this.format.onBattleStart?.call(this);
 			for (const rule of this.ruleTable.keys()) {
 				if ('+*-!'.includes(rule.charAt(0))) continue;
 				const subFormat = this.dex.formats.get(rule);
-				if (subFormat.onBattleStart) subFormat.onBattleStart.call(this);
+				subFormat.onBattleStart?.call(this);
 			}
 
 			for (const side of this.sides) {
diff --git a/data/mods/gen9ssb/scripts.ts b/data/mods/gen9ssb/scripts.ts
index 62ee0a19d4..9a11f8846a 100644
--- a/data/mods/gen9ssb/scripts.ts
+++ b/data/mods/gen9ssb/scripts.ts
@@ -369,6 +369,7 @@ export const Scripts: ModdedBattleScriptsData = {
 		case 'start': {
 			for (const side of this.sides) {
 				if (side.pokemonLeft) side.pokemonLeft = side.pokemon.length;
+				this.add('teamsize', side.id, side.pokemon.length);
 			}
 
 			this.add('start');
@@ -409,11 +410,11 @@ export const Scripts: ModdedBattleScriptsData = {
 				}
 			}
 
-			if (this.format.onBattleStart) this.format.onBattleStart.call(this);
+			this.format.onBattleStart?.call(this);
 			for (const rule of this.ruleTable.keys()) {
 				if ('+*-!'.includes(rule.charAt(0))) continue;
 				const subFormat = this.dex.formats.get(rule);
-				if (subFormat.onBattleStart) subFormat.onBattleStart.call(this);
+				subFormat.onBattleStart?.call(this);
 			}
 
 			for (const side of this.sides) {
diff --git a/data/mods/mixandmega/scripts.ts b/data/mods/mixandmega/scripts.ts
index 431575013e..e2ca07864c 100644
--- a/data/mods/mixandmega/scripts.ts
+++ b/data/mods/mixandmega/scripts.ts
@@ -42,10 +42,6 @@ export const Scripts: ModdedBattleScriptsData = {
 			}
 		}
 
-		for (const side of this.sides) {
-			this.add('teamsize', side.id, side.pokemon.length);
-		}
-
 		this.add('gen', this.gen);
 
 		this.add('tier', format.name);
@@ -54,11 +50,11 @@ export const Scripts: ModdedBattleScriptsData = {
 			this.add('rated', typeof this.rated === 'string' ? this.rated : '');
 		}
 
-		if (format.onBegin) format.onBegin.call(this);
+		format.onBegin?.call(this);
 		for (const rule of this.ruleTable.keys()) {
 			if ('+*-!'.includes(rule.charAt(0))) continue;
 			const subFormat = this.dex.formats.get(rule);
-			if (subFormat.onBegin) subFormat.onBegin.call(this);
+			subFormat.onBegin?.call(this);
 		}
 		for (const pokemon of this.getAllPokemon()) {
 			const item = pokemon.getItem();
@@ -87,11 +83,25 @@ export const Scripts: ModdedBattleScriptsData = {
 			this.add(`raw|<div class="infobox"><details class="readmore"${open}><summary><strong>${format.customRules.length} custom rule${plural}:</strong></summary> ${format.customRules.join(', ')}</details></div>`);
 		}
 
-		if (format.onTeamPreview) format.onTeamPreview.call(this);
+		format.onTeamPreview?.call(this);
 		for (const rule of this.ruleTable.keys()) {
 			if ('+*-!'.includes(rule.charAt(0))) continue;
 			const subFormat = this.dex.formats.get(rule);
-			if (subFormat.onTeamPreview) subFormat.onTeamPreview.call(this);
+			subFormat.onTeamPreview?.call(this);
+		}
+
+		if (this.requestState !== 'teampreview' && this.ruleTable.pickedTeamSize) {
+			this.add('clearpoke');
+			for (const side of this.sides) {
+				for (const pokemon of side.pokemon) {
+					// Still need to hide these formes since they change on battle start
+					const details = pokemon.details.replace(', shiny', '')
+						.replace(/(Zacian|Zamazenta)(?!-Crowned)/g, '$1-*')
+						.replace(/(Xerneas)(-[a-zA-Z?-]+)?/g, '$1-*');
+					this.addSplit(side.id, ['poke', pokemon.side.id, details, '']);
+				}
+			}
+			this.makeRequest('teampreview');
 		}
 
 		this.queue.addChoice({ choice: 'start' });
@@ -106,6 +116,7 @@ export const Scripts: ModdedBattleScriptsData = {
 		case 'start': {
 			for (const side of this.sides) {
 				if (side.pokemonLeft) side.pokemonLeft = side.pokemon.length;
+				this.add('teamsize', side.id, side.pokemon.length);
 			}
 
 			this.add('start');
@@ -147,11 +158,11 @@ export const Scripts: ModdedBattleScriptsData = {
 				}
 			}
 
-			if (this.format.onBattleStart) this.format.onBattleStart.call(this);
+			this.format.onBattleStart?.call(this);
 			for (const rule of this.ruleTable.keys()) {
 				if ('+*-!'.includes(rule.charAt(0))) continue;
 				const subFormat = this.dex.formats.get(rule);
-				if (subFormat.onBattleStart) subFormat.onBattleStart.call(this);
+				subFormat.onBattleStart?.call(this);
 			}
 
 			for (const side of this.sides) {
diff --git a/data/mods/monkeyspaw/scripts.ts b/data/mods/monkeyspaw/scripts.ts
index cf384d3623..dd9a604e34 100644
--- a/data/mods/monkeyspaw/scripts.ts
+++ b/data/mods/monkeyspaw/scripts.ts
@@ -188,6 +188,7 @@ export const Scripts: ModdedBattleScriptsData = {
 		case 'start': {
 			for (const side of this.sides) {
 				if (side.pokemonLeft) side.pokemonLeft = side.pokemon.length;
+				this.add('teamsize', side.id, side.pokemon.length);
 			}
 
 			this.add('start');
@@ -228,11 +229,11 @@ export const Scripts: ModdedBattleScriptsData = {
 				}
 			}
 
-			if (this.format.onBattleStart) this.format.onBattleStart.call(this);
+			this.format.onBattleStart?.call(this);
 			for (const rule of this.ruleTable.keys()) {
 				if ('+*-!'.includes(rule.charAt(0))) continue;
 				const subFormat = this.dex.formats.get(rule);
-				if (subFormat.onBattleStart) subFormat.onBattleStart.call(this);
+				subFormat.onBattleStart?.call(this);
 			}
 
 			for (const side of this.sides) {
diff --git a/data/mods/randomroulette/scripts.ts b/data/mods/randomroulette/scripts.ts
index a0ab26978c..9df29569da 100644
--- a/data/mods/randomroulette/scripts.ts
+++ b/data/mods/randomroulette/scripts.ts
@@ -80,10 +80,6 @@ export const Scripts: ModdedBattleScriptsData = {
 			}
 		}
 
-		for (const side of this.sides) {
-			this.add('teamsize', side.id, side.pokemon.length);
-		}
-
 		this.add('gen', this.gen);
 
 		this.add('tier', format.name);
@@ -92,11 +88,11 @@ export const Scripts: ModdedBattleScriptsData = {
 			this.add('rated', typeof this.rated === 'string' ? this.rated : '');
 		}
 
-		if (format.onBegin) format.onBegin.call(this);
+		format.onBegin?.call(this);
 		for (const rule of this.ruleTable.keys()) {
 			if ('+*-!'.includes(rule.charAt(0))) continue;
 			const subFormat = this.dex.formats.get(rule);
-			if (subFormat.onBegin) subFormat.onBegin.call(this);
+			subFormat.onBegin?.call(this);
 		}
 
 		if (this.sides.some(side => !side.pokemon[0])) {
@@ -113,11 +109,25 @@ export const Scripts: ModdedBattleScriptsData = {
 			this.add(`raw|<div class="infobox"><details class="readmore"${open}><summary><strong>${format.customRules.length} custom rule${plural}:</strong></summary> ${format.customRules.join(', ')}</details></div>`);
 		}
 
-		if (format.onTeamPreview) format.onTeamPreview.call(this);
+		format.onTeamPreview?.call(this);
 		for (const rule of this.ruleTable.keys()) {
 			if ('+*-!'.includes(rule.charAt(0))) continue;
 			const subFormat = this.dex.formats.get(rule);
-			if (subFormat.onTeamPreview) subFormat.onTeamPreview.call(this);
+			subFormat.onTeamPreview?.call(this);
+		}
+
+		if (this.requestState !== 'teampreview' && this.ruleTable.pickedTeamSize) {
+			this.add('clearpoke');
+			for (const side of this.sides) {
+				for (const pokemon of side.pokemon) {
+					// Still need to hide these formes since they change on battle start
+					const details = pokemon.details.replace(', shiny', '')
+						.replace(/(Zacian|Zamazenta)(?!-Crowned)/g, '$1-*')
+						.replace(/(Xerneas)(-[a-zA-Z?-]+)?/g, '$1-*');
+					this.addSplit(side.id, ['poke', pokemon.side.id, details, '']);
+				}
+			}
+			this.makeRequest('teampreview');
 		}
 
 		this.queue.addChoice({ choice: 'start' });
diff --git a/data/rulesets.ts b/data/rulesets.ts
index dd637762ea..acb6c1f924 100644
--- a/data/rulesets.ts
+++ b/data/rulesets.ts
@@ -1976,12 +1976,7 @@ export const Rulesets: import('../sim/dex-formats').FormatDataTable = {
 		name: 'Picked Team Size',
 		desc: "Team size (number of pokemon) that can be brought out of Team Preview",
 		hasValue: 'positive-integer',
-		// hardcoded in sim/side
-		onValidateRule() {
-			if (!(this.ruleTable.has('teampreview') || this.ruleTable.has('teamtypepreview'))) {
-				throw new Error(`The "Picked Team Size" rule${this.ruleTable.blame('pickedteamsize')} requires Team Preview.`);
-			}
-		},
+		// hardcoded in sim/side and sim/battle
 	},
 	minteamsize: {
 		effectType: 'ValidatorRule',
diff --git a/sim/battle.ts b/sim/battle.ts
index d0df521c08..f1799dc312 100644
--- a/sim/battle.ts
+++ b/sim/battle.ts
@@ -1868,10 +1868,6 @@ export class Battle {
 			}
 		}
 
-		for (const side of this.sides) {
-			this.add('teamsize', side.id, side.pokemon.length);
-		}
-
 		this.add('gen', this.gen);
 
 		this.add('tier', format.name);
@@ -1908,6 +1904,20 @@ export class Battle {
 			subFormat.onTeamPreview?.call(this);
 		}
 
+		if (this.requestState !== 'teampreview' && this.ruleTable.pickedTeamSize) {
+			this.add('clearpoke');
+			for (const side of this.sides) {
+				for (const pokemon of side.pokemon) {
+					// Still need to hide these formes since they change on battle start
+					const details = pokemon.details.replace(', shiny', '')
+						.replace(/(Zacian|Zamazenta)(?!-Crowned)/g, '$1-*')
+						.replace(/(Xerneas)(-[a-zA-Z?-]+)?/g, '$1-*');
+					this.addSplit(side.id, ['poke', pokemon.side.id, details, '']);
+				}
+			}
+			this.makeRequest('teampreview');
+		}
+
 		this.queue.addChoice({ choice: 'start' });
 		this.midTurn = true;
 		if (!this.requestState) this.turnLoop();
@@ -2601,6 +2611,7 @@ export class Battle {
 		case 'start': {
 			for (const side of this.sides) {
 				if (side.pokemonLeft) side.pokemonLeft = side.pokemon.length;
+				this.add('teamsize', side.id, side.pokemon.length);
 			}
 
 			this.add('start');
@@ -2641,11 +2652,11 @@ export class Battle {
 				}
 			}
 
-			if (this.format.onBattleStart) this.format.onBattleStart.call(this);
+			this.format.onBattleStart?.call(this);
 			for (const rule of this.ruleTable.keys()) {
 				if ('+*-!'.includes(rule.charAt(0))) continue;
 				const subFormat = this.dex.formats.get(rule);
-				if (subFormat.onBattleStart) subFormat.onBattleStart.call(this);
+				subFormat.onBattleStart?.call(this);
 			}
 
 			for (const side of this.sides) {