From 10429ec01f971d30709326fb90b5e43dd381f9e2 Mon Sep 17 00:00:00 2001
From: Shriansh Chari <30420527+shrianshChari@users.noreply.github.com>
Date: Thu, 13 Jul 2023 00:34:04 -0700
Subject: [PATCH 1/2] Gen 4: Fix Klutz not dropping Speed from Iron Ball

---
 calc/src/mechanics/gen4.ts | 5 +++--
 calc/src/mechanics/util.ts | 4 +++-
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/calc/src/mechanics/gen4.ts b/calc/src/mechanics/gen4.ts
index 59c1aac9d..b84a4da30 100644
--- a/calc/src/mechanics/gen4.ts
+++ b/calc/src/mechanics/gen4.ts
@@ -144,8 +144,9 @@ export function calculateDPP(
 
   let typeEffectiveness = type1Effectiveness * type2Effectiveness;
 
-  // Iron Ball ignores Klutz in generation 4
-  if (typeEffectiveness === 0 && move.hasType('Ground') && defender.hasItem('Iron Ball')) {
+  // Klutz doesn't let Iron Ball ground in generation 4
+  if (typeEffectiveness === 0 && move.hasType('Ground') &&
+    (defender.hasItem('Iron Ball') && defender.ability! !== 'Klutz')) {
     if (type1Effectiveness === 0) {
       type1Effectiveness = 1;
     } else if (defender.types[1] && type2Effectiveness === 0) {
diff --git a/calc/src/mechanics/util.ts b/calc/src/mechanics/util.ts
index 7ff91b9c7..cad795610 100644
--- a/calc/src/mechanics/util.ts
+++ b/calc/src/mechanics/util.ts
@@ -190,9 +190,11 @@ export function checkForecast(pokemon: Pokemon, weather?: Weather) {
 }
 
 export function checkItem(pokemon: Pokemon, magicRoomActive?: boolean) {
+  // Pokemon with Klutz still get their speed dropped in generation 4
+  if (pokemon.gen.num === 4 && pokemon.item! === 'Iron Ball') return;
   if (
     pokemon.hasAbility('Klutz') && !EV_ITEMS.includes(pokemon.item!) ||
-      magicRoomActive
+    magicRoomActive
   ) {
     pokemon.item = '' as ItemName;
   }

From 5c594f34d63a8b2176f85cbbce927ab65902a551 Mon Sep 17 00:00:00 2001
From: Shriansh Chari <30420527+shrianshChari@users.noreply.github.com>
Date: Sat, 7 Oct 2023 12:15:36 -0400
Subject: [PATCH 2/2] Use methods of Pokemon instead of equality checks

---
 calc/src/mechanics/gen4.ts | 2 +-
 calc/src/mechanics/util.ts | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/calc/src/mechanics/gen4.ts b/calc/src/mechanics/gen4.ts
index b84a4da30..656ef34b5 100644
--- a/calc/src/mechanics/gen4.ts
+++ b/calc/src/mechanics/gen4.ts
@@ -146,7 +146,7 @@ export function calculateDPP(
 
   // Klutz doesn't let Iron Ball ground in generation 4
   if (typeEffectiveness === 0 && move.hasType('Ground') &&
-    (defender.hasItem('Iron Ball') && defender.ability! !== 'Klutz')) {
+    (defender.hasItem('Iron Ball') && !defender.hasAbility('Klutz'))) {
     if (type1Effectiveness === 0) {
       type1Effectiveness = 1;
     } else if (defender.types[1] && type2Effectiveness === 0) {
diff --git a/calc/src/mechanics/util.ts b/calc/src/mechanics/util.ts
index cad795610..e707d60b0 100644
--- a/calc/src/mechanics/util.ts
+++ b/calc/src/mechanics/util.ts
@@ -191,7 +191,7 @@ export function checkForecast(pokemon: Pokemon, weather?: Weather) {
 
 export function checkItem(pokemon: Pokemon, magicRoomActive?: boolean) {
   // Pokemon with Klutz still get their speed dropped in generation 4
-  if (pokemon.gen.num === 4 && pokemon.item! === 'Iron Ball') return;
+  if (pokemon.gen.num === 4 && pokemon.hasItem('Iron Ball')) return;
   if (
     pokemon.hasAbility('Klutz') && !EV_ITEMS.includes(pokemon.item!) ||
     magicRoomActive