diff --git a/data/events/magikarp_lengths.asm b/data/events/magikarp_lengths.asm
index 1a1040d6c68..3a6b9e1ea21 100644
--- a/data/events/magikarp_lengths.asm
+++ b/data/events/magikarp_lengths.asm
@@ -2,9 +2,7 @@ MagikarpLengths:
 ; [wMagikarpLength] = z * 100 + (bc - x) / y
 ; First argument is the bc threshold as well as x.
 ; Second argument is y.
-; In reality, due to the bug at .BCLessThanDE,
-; the threshold is determined by only register b.
-	dwb   110, 1 ; not used unless the bug is fixed
+	dwb   110, 1
 	dwb   310, 2
 	dwb   710, 4
 	dwb  2710, 20
@@ -17,4 +15,4 @@ MagikarpLengths:
 	dwb 64710, 20
 	dwb 65210, 5
 	dwb 65410, 2
-	dwb 65510, 1 ; not used
+	dwb 65510, 1
diff --git a/docs/bugs_and_glitches.md b/docs/bugs_and_glitches.md
index 77152efb5c0..25fcc14fdd7 100644
--- a/docs/bugs_and_glitches.md
+++ b/docs/bugs_and_glitches.md
@@ -2407,6 +2407,8 @@ CopyPokemonName_Buffer1_Buffer3:
 
 ### Magikarp lengths can be miscalculated
 
+`CalcMagikarpLength.BCLessThanDE` only compares the high bytes of `bc` and `de`. This causes the first entry of the `MagikarpLengths` table to go unused, and `bc` values between 65,280 and 65,509 to use the wrong formula. As a side effect, the highest possible length is capped at 1,625mm (before being converted to feet and inches).
+
 **Fix:** Edit `CalcMagikarpLength.BCLessThanDE` in [engine/events/magikarp.asm](https://github.com/pret/pokecrystal/blob/master/engine/events/magikarp.asm):
 
 ```diff
@@ -2414,8 +2416,9 @@ CopyPokemonName_Buffer1_Buffer3:
 -; BUG: Magikarp lengths can be miscalculated (see docs/bugs_and_glitches.md)
  	ld a, b
  	cp d
- 	ret c
+-	ret c
 -	ret nc
++	ret nz
  	ld a, c
  	cp e
  	ret
diff --git a/engine/events/magikarp.asm b/engine/events/magikarp.asm
index 09d75967e5e..d5d2c5ecb54 100644
--- a/engine/events/magikarp.asm
+++ b/engine/events/magikarp.asm
@@ -108,36 +108,18 @@ CalcMagikarpLength:
 ;   de: wEnemyMonDVs
 ;   bc: wPlayerID
 
-; This function is poorly commented.
-
-; In short, it generates a value between 190 and 1786 using
-; a Magikarp's DVs and its trainer ID. This value is further
-; filtered in LoadEnemyMon to make longer Magikarp even rarer.
+; It generates a value between 190 and 1755 using a Magikarp's DVs
+; and its trainer ID. This value is further filtered in LoadEnemyMon
+; to make longer Magikarp even rarer.
 
 ; The value is generated from a lookup table.
-; The index is determined by the dv xored with the player's trainer id.
-
-; bc = rrc(dv[0]) ++ rrc(dv[1]) ^ rrc(id)
+; The index is determined by the DV xored with the player's trainer ID
+; and then stored in bc.
 
-; if bc < 10:    [wMagikarpLength] = c + 190
-; if bc ≥ $ff00: [wMagikarpLength] = c + 1370
+; if bc < 10:    [wMagikarpLength] = bc + 190
+; if bc ≥ 65510: [wMagikarpLength] = bc - 65510 + 1600
 ; else:          [wMagikarpLength] = z * 100 + (bc - x) / y
 
-; X, Y, and Z depend on the value of b as follows:
-
-; if b = 0:        x =   310,  y =   2,  z =  3
-; if b = 1:        x =   710,  y =   4,  z =  4
-; if b = 2-9:      x =  2710,  y =  20,  z =  5
-; if b = 10-29:    x =  7710,  y =  50,  z =  6
-; if b = 30-68:    x = 17710,  y = 100,  z =  7
-; if b = 69-126:   x = 32710,  y = 150,  z =  8
-; if b = 127-185:  x = 47710,  y = 150,  z =  9
-; if b = 186-224:  x = 57710,  y = 100,  z = 10
-; if b = 225-243:  x = 62710,  y =  50,  z = 11
-; if b = 244-251:  x = 64710,  y =  20,  z = 12
-; if b = 252-253:  x = 65210,  y =   5,  z = 13
-; if b = 254:      x = 65410,  y =   2,  z = 14
-
 	; bc = rrc(dv[0]) ++ rrc(dv[1]) ^ rrc(id)
 
 	; id