diff --git a/docs/changelogs/1.9.x/1.9.0.md b/docs/changelogs/1.9.x/1.9.0.md
index 16947711d3e2..0d39f109ed69 100644
--- a/docs/changelogs/1.9.x/1.9.0.md
+++ b/docs/changelogs/1.9.x/1.9.0.md
@@ -43,7 +43,7 @@
     * Migration script available in `migration_scripts/egg_move_refactor.py` by @AlexOn1ine in https://github.com/rh-hideout/pokeemerald-expansion/pull/5040
 * Added documentation to `STATIC_ASSERTS` used by the `BoxPokemon` after 1.8.0 by @pkmnsnfrn in https://github.com/rh-hideout/pokeemerald-expansion/pull/4294
 * #### Competitive-formatted parties by @mrgriffin in https://github.com/rh-hideout/pokeemerald-expansion/pull/3545
-    * Can be disabled by setting `COMPETITIVE_PARTY_SYNTAX` to `FALSE` in `include/config/general.h`.
+    * Can be disabled by setting `COMPETITIVE_PARTY_SYNTAX` to `FALSE` in `include/config/general.h`. If migrating from 1.8, remove the first and last lines from `src/data/trainers.h` (`const struct Trainer gTrainers[] = {` and `};` respectively).
     * Introduces `trainerproc`, a tool which converts Competitive-formatted parties into Trainer Control-formatted parties.
     * If you made custom changes to the following files and want to use this new format, ***Do not accept the incoming changes for them.*** Instead, use the migration script present in `migration_scripts/convert_parties.py`:
         - `src/data/trainers.h`
diff --git a/graphics/pokemon/urshifu/front.png b/graphics/pokemon/urshifu/front.png
index cbb462be2ea0..468ba31f7090 100644
Binary files a/graphics/pokemon/urshifu/front.png and b/graphics/pokemon/urshifu/front.png differ
diff --git a/graphics/pokemon/urshifu/rapid_strike_style/front.png b/graphics/pokemon/urshifu/rapid_strike_style/front.png
index 09d72971424b..d06637f4e173 100644
Binary files a/graphics/pokemon/urshifu/rapid_strike_style/front.png and b/graphics/pokemon/urshifu/rapid_strike_style/front.png differ
diff --git a/include/battle.h b/include/battle.h
index c48dc7883504..1aa26a9470be 100644
--- a/include/battle.h
+++ b/include/battle.h
@@ -795,6 +795,7 @@ struct BattleStruct
     u8 quickClawRandom[MAX_BATTLERS_COUNT];
     u8 quickDrawRandom[MAX_BATTLERS_COUNT];
     u8 shellSideArmCategory[MAX_BATTLERS_COUNT][MAX_BATTLERS_COUNT];
+    u8 speedTieBreaks; // MAX_BATTLERS_COUNT! values.
     u8 boosterEnergyActivates;
     u8 distortedTypeMatchups;
     u8 categoryOverride; // for Z-Moves and Max Moves
diff --git a/include/battle_main.h b/include/battle_main.h
index 59a515b50843..eb0af5aa776a 100644
--- a/include/battle_main.h
+++ b/include/battle_main.h
@@ -75,6 +75,7 @@ s8 GetChosenMovePriority(u32 battlerId);
 s8 GetMovePriority(u32 battlerId, u16 move);
 s32 GetWhichBattlerFasterArgs(u32 battler1, u32 battler2, bool32 ignoreChosenMoves, u32 ability1, u32 ability2,
                               u32 holdEffectBattler1, u32 holdEffectBattler2, u32 speedBattler1, u32 speedBattler2, s32 priority1, s32 priority2);
+s32 GetWhichBattlerFasterOrTies(u32 battler1, u32 battler2, bool32 ignoreChosenMoves);
 s32 GetWhichBattlerFaster(u32 battler1, u32 battler2, bool32 ignoreChosenMoves);
 void RunBattleScriptCommands_PopCallbacksStack(void);
 void RunBattleScriptCommands(void);
diff --git a/src/battle_ai_main.c b/src/battle_ai_main.c
index 08b8e4335cec..63bab46ec92d 100644
--- a/src/battle_ai_main.c
+++ b/src/battle_ai_main.c
@@ -2722,7 +2722,7 @@ static s32 AI_TryToFaint(u32 battlerAtk, u32 battlerDef, u32 move, s32 score)
             ADJUST_SCORE(SLOW_KILL);
     }
     else if (CanTargetFaintAi(battlerDef, battlerAtk)
-            && GetWhichBattlerFaster(battlerAtk, battlerDef, TRUE) != AI_IS_FASTER
+            && GetWhichBattlerFasterOrTies(battlerAtk, battlerDef, TRUE) != AI_IS_FASTER
             && GetMovePriority(battlerAtk, move) > 0)
     {
         ADJUST_SCORE(LAST_CHANCE);
@@ -4117,7 +4117,7 @@ static u32 AI_CalcMoveEffectScore(u32 battlerAtk, u32 battlerDef, u32 move)
             if (IsStatBoostingBerry(item) && aiData->hpPercents[battlerAtk] > 60)
                 ADJUST_SCORE(WEAK_EFFECT);
             else if (ShouldRestoreHpBerry(battlerAtk, item) && !CanAIFaintTarget(battlerAtk, battlerDef, 0)
-              && ((GetWhichBattlerFaster(battlerAtk, battlerDef, TRUE) == 1 && CanTargetFaintAiWithMod(battlerDef, battlerAtk, 0, 0))
+              && ((GetWhichBattlerFasterOrTies(battlerAtk, battlerDef, TRUE) == 1 && CanTargetFaintAiWithMod(battlerDef, battlerAtk, 0, 0))
                || !CanTargetFaintAiWithMod(battlerDef, battlerAtk, toHeal, 0)))
                 ADJUST_SCORE(WEAK_EFFECT);    // Recycle healing berry if we can't otherwise faint the target and the target wont kill us after we activate the berry
         }
diff --git a/src/battle_main.c b/src/battle_main.c
index 2b95bad97563..9df19b9566cf 100644
--- a/src/battle_main.c
+++ b/src/battle_main.c
@@ -120,6 +120,7 @@ static void SpriteCB_UnusedBattleInit(struct Sprite *sprite);
 static void SpriteCB_UnusedBattleInit_Main(struct Sprite *sprite);
 static u32 Crc32B (const u8 *data, u32 size);
 static u32 GeneratePartyHash(const struct Trainer *trainer, u32 i);
+static s32 Factorial(s32);
 
 EWRAM_DATA u16 gBattle_BG0_X = 0;
 EWRAM_DATA u16 gBattle_BG0_Y = 0;
@@ -3807,6 +3808,8 @@ static void TryDoEventsBeforeFirstTurn(void)
         }
         #endif // TESTING
 
+        gBattleStruct->speedTieBreaks = RandomUniform(RNG_SPEED_TIE, 0, Factorial(MAX_BATTLERS_COUNT) - 1);
+
         for (i = 0; i < gBattlersCount; i++)
             gBattlerByTurnOrder[i] = i;
         for (i = 0; i < gBattlersCount - 1; i++)
@@ -3977,6 +3980,8 @@ void BattleTurnPassed(void)
 {
     s32 i;
 
+    gBattleStruct->speedTieBreaks = RandomUniform(RNG_SPEED_TIE, 0, Factorial(MAX_BATTLERS_COUNT) - 1);
+
     TurnValuesCleanUp(TRUE);
     if (gBattleOutcome == 0)
     {
@@ -4865,9 +4870,10 @@ s32 GetWhichBattlerFasterArgs(u32 battler1, u32 battler2, bool32 ignoreChosenMov
             strikesFirst = 1;
         else
         {
-            if (speedBattler1 == speedBattler2 && Random() & 1)
+            if (speedBattler1 == speedBattler2)
             {
-                strikesFirst = 0; // same speeds, same priorities
+                // same speeds, same priorities
+                strikesFirst = 0;
             }
             else if (speedBattler1 < speedBattler2)
             {
@@ -4898,7 +4904,7 @@ s32 GetWhichBattlerFasterArgs(u32 battler1, u32 battler2, bool32 ignoreChosenMov
     return strikesFirst;
 }
 
-s32 GetWhichBattlerFaster(u32 battler1, u32 battler2, bool32 ignoreChosenMoves)
+s32 GetWhichBattlerFasterOrTies(u32 battler1, u32 battler2, bool32 ignoreChosenMoves)
 {
     s32 priority1 = 0, priority2 = 0;
     u32 ability1 = GetBattlerAbility(battler1);
@@ -4916,8 +4922,60 @@ s32 GetWhichBattlerFaster(u32 battler1, u32 battler2, bool32 ignoreChosenMoves)
             priority2 = GetChosenMovePriority(battler2);
     }
 
-    return GetWhichBattlerFasterArgs(battler1, battler2, ignoreChosenMoves, ability1, ability2,
-                                     holdEffectBattler1, holdEffectBattler2, speedBattler1, speedBattler2, priority1, priority2);
+    return GetWhichBattlerFasterArgs(
+        battler1, battler2,
+        ignoreChosenMoves,
+        ability1, ability2,
+        holdEffectBattler1, holdEffectBattler2,
+        speedBattler1, speedBattler2,
+        priority1, priority2
+    );
+}
+
+// 24 == MAX_BATTLERS_COUNT!.
+// These are the possible orders if all the battlers speed tie. An order
+// is chosen at the start of the turn.
+static const u8 sBattlerOrders[24][4] =
+{
+    { 0, 1, 2, 3 },
+    { 0, 1, 3, 2 },
+    { 0, 2, 1, 3 },
+    { 0, 2, 3, 1 },
+    { 0, 3, 1, 2 },
+    { 0, 3, 2, 1 },
+    { 1, 0, 2, 3 },
+    { 1, 0, 3, 2 },
+    { 1, 2, 0, 3 },
+    { 1, 2, 3, 0 },
+    { 1, 3, 0, 2 },
+    { 1, 3, 2, 0 },
+    { 2, 0, 1, 3 },
+    { 2, 0, 3, 1 },
+    { 2, 1, 0, 3 },
+    { 2, 1, 3, 0 },
+    { 2, 3, 0, 1 },
+    { 2, 3, 1, 0 },
+    { 3, 0, 1, 2 },
+    { 3, 0, 2, 1 },
+    { 3, 1, 0, 2 },
+    { 3, 1, 2, 0 },
+    { 3, 2, 0, 1 },
+    { 3, 2, 1, 0 },
+};
+
+s32 GetWhichBattlerFaster(u32 battler1, u32 battler2, bool32 ignoreChosenMoves)
+{
+    s32 strikesFirst = GetWhichBattlerFasterOrTies(battler1, battler2, ignoreChosenMoves);
+    if (strikesFirst == 0)
+    {
+        s32 order1 = sBattlerOrders[gBattleStruct->speedTieBreaks][battler1];
+        s32 order2 = sBattlerOrders[gBattleStruct->speedTieBreaks][battler2];
+        if (order1 < order2)
+            strikesFirst = 1;
+        else
+            strikesFirst = -1;
+    }
+    return strikesFirst;
 }
 
 static void SetActionsAndBattlersTurnOrder(void)
@@ -5890,3 +5948,11 @@ bool32 IsWildMonSmart(void)
     return FALSE;
 #endif
 }
+
+static s32 Factorial(s32 n)
+{
+    s32 f = 1, i;
+    for (i = 2; i <= n; i++)
+        f *= i;
+    return f;
+}
diff --git a/test/battle/ability/comatose.c b/test/battle/ability/comatose.c
index bd991c258eb9..cc65e9afac7e 100644
--- a/test/battle/ability/comatose.c
+++ b/test/battle/ability/comatose.c
@@ -34,7 +34,10 @@ SINGLE_BATTLE_TEST("Comatose may be suppressed if pokemon transformed into a pok
     PARAMETRIZE { move = MOVE_THUNDER_WAVE; }
 
     GIVEN {
-        PLAYER(SPECIES_KOMALA) { Ability(ABILITY_COMATOSE); Speed(30); }
+        // FIXME: Explicit moves currently required here because Ditto
+        // expects to find Celebrate in slot 1 during the second turn
+        // (after transforming).
+        PLAYER(SPECIES_KOMALA) { Ability(ABILITY_COMATOSE); Speed(30); Moves(MOVE_CELEBRATE, MOVE_GASTRO_ACID, move); }
         OPPONENT(SPECIES_DITTO) { Speed(20); }
     } WHEN {
         TURN { MOVE(player, MOVE_GASTRO_ACID); MOVE(opponent, MOVE_TRANSFORM); }
diff --git a/test/battle/move.c b/test/battle/move.c
index 936a821081b6..228a09a7c665 100644
--- a/test/battle/move.c
+++ b/test/battle/move.c
@@ -66,10 +66,9 @@ SINGLE_BATTLE_TEST("Turn order is determined by Speed if priority ties")
     }
 }
 
-SINGLE_BATTLE_TEST("Turn order is determined randomly if priority and Speed tie")
+SINGLE_BATTLE_TEST("Turn order is determined randomly if priority and Speed tie [singles]")
 {
-    KNOWN_FAILING; // The algorithm is significantly biased.
-    PASSES_RANDOMLY(1, 2);
+    PASSES_RANDOMLY(1, 2, RNG_SPEED_TIE);
     GIVEN {
         PLAYER(SPECIES_WOBBUFFET) { Speed(1); }
         OPPONENT(SPECIES_WOBBUFFET) { Speed(1); }
@@ -81,6 +80,60 @@ SINGLE_BATTLE_TEST("Turn order is determined randomly if priority and Speed tie"
     }
 }
 
+DOUBLE_BATTLE_TEST("Turn order is determined randomly if priority and Speed tie [doubles]")
+{
+    struct BattlePokemon *order[4] = { NULL, NULL, NULL, NULL };
+    u32 a, b, c, d;
+
+    // TODO: Test all of these in a single PASSES_RANDOMLY pass rather
+    // than 24 PARAMETRIZEd passes.
+    PARAMETRIZE { a = 0; b = 1; c = 2; d = 3; }
+    PARAMETRIZE { a = 0; b = 1; c = 3; d = 2; }
+    PARAMETRIZE { a = 0; b = 2; c = 1; d = 3; }
+    PARAMETRIZE { a = 0; b = 2; c = 3; d = 1; }
+    PARAMETRIZE { a = 0; b = 3; c = 1; d = 2; }
+    PARAMETRIZE { a = 0; b = 3; c = 2; d = 1; }
+    PARAMETRIZE { a = 1; b = 0; c = 2; d = 3; }
+    PARAMETRIZE { a = 1; b = 0; c = 3; d = 2; }
+    PARAMETRIZE { a = 1; b = 2; c = 0; d = 3; }
+    PARAMETRIZE { a = 1; b = 2; c = 3; d = 0; }
+    PARAMETRIZE { a = 1; b = 3; c = 0; d = 2; }
+    PARAMETRIZE { a = 1; b = 3; c = 2; d = 0; }
+    PARAMETRIZE { a = 2; b = 0; c = 1; d = 3; }
+    PARAMETRIZE { a = 2; b = 0; c = 3; d = 1; }
+    PARAMETRIZE { a = 2; b = 1; c = 0; d = 3; }
+    PARAMETRIZE { a = 2; b = 1; c = 3; d = 0; }
+    PARAMETRIZE { a = 2; b = 3; c = 0; d = 1; }
+    PARAMETRIZE { a = 2; b = 3; c = 1; d = 0; }
+    PARAMETRIZE { a = 3; b = 0; c = 1; d = 2; }
+    PARAMETRIZE { a = 3; b = 0; c = 2; d = 1; }
+    PARAMETRIZE { a = 3; b = 1; c = 0; d = 2; }
+    PARAMETRIZE { a = 3; b = 1; c = 2; d = 0; }
+    PARAMETRIZE { a = 3; b = 2; c = 0; d = 1; }
+    PARAMETRIZE { a = 3; b = 2; c = 1; d = 0; }
+
+    order[a] = playerLeft;
+    order[b] = playerRight;
+    order[c] = opponentLeft;
+    order[d] = opponentRight;
+
+    PASSES_RANDOMLY(1, 24, RNG_SPEED_TIE);
+
+    GIVEN {
+        PLAYER(SPECIES_WOBBUFFET) { Speed(1); }
+        PLAYER(SPECIES_WYNAUT) { Speed(1); }
+        OPPONENT(SPECIES_WOBBUFFET) { Speed(1); }
+        OPPONENT(SPECIES_WYNAUT) { Speed(1); }
+    } WHEN {
+        TURN { MOVE(playerLeft, MOVE_SPLASH); MOVE(playerRight, MOVE_SPLASH); MOVE(opponentLeft, MOVE_SPLASH); MOVE(opponentRight, MOVE_SPLASH); }
+    } SCENE {
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_SPLASH, order[0]);
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_SPLASH, order[1]);
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_SPLASH, order[2]);
+        ANIMATION(ANIM_TYPE_MOVE, MOVE_SPLASH, order[3]);
+    }
+}
+
 SINGLE_BATTLE_TEST("Critical hits occur at a 1/24 rate")
 {
     ASSUME(B_CRIT_CHANCE >= GEN_7);