Blaster Master Area 4 and 7 Bosses

Blaster Master Area 4 and 7 Bosses
by ZeroNoin

The bosses of Area 4 and 7 in Blaster Master (the frogs, green and orange) can at times be a bit tricky in positioning and timing the grenade pause glitch.  However, I have found that positioning your character at the top of the room has advantages.

Basically there is a blind spot for the frog bosses' body's hurtbox at the top of the room.  If your character is 0 to 7 pixels from the top possible position on the room, the frogs' bodies will not hit you.  This excludes the starting position of the boss of Area 4; it begins at the top of the room, but after it jumps one time, it moves down and does not go higher again.  The only thing that can hit you while at the top of the room is aimed fire shots.

Because each frog boss begins at the top of the room, standing at the top of the room in this blind area makes it easier to get in position quickly for the grenade glitch when the frogs open their mouths.  At 0 to 7 pixels from the top of the room, you can simply stand behind the frogs and do a normal grenade throw onto their hitbox.  Their hitbox seems to be a single pixel on the middle front of the nose.

Facing your character downward and holding A (to hold him facing downward) before shooting grenades can help.  You may prefer to stand a bit to the side to add a timing buffer for the grenade.  You may also prefer just to move normally and tap downward before the grenade glitch shot.  Keep in mind your character moves at 1.5 pixels per frame.

The positioning of your character can also control whether the high-pitched blocking noise occurs during the grenade glitch.  If your character is 0 to 4 pixels from the top of the room, a normal grenade throw will always produce the sound; if your character is 5 to 7 pixels from the top, the sound will not occur.  Since you know the grenade glitch kill is complete when the sound changes from the damage sound to the kill sound (and likely prefer not having the blocking noise), controlling whether the noise occurs can help.  While facing downward and holding A, you can compare the pixels of your character with the pixels of the back wall or floor and/or frog features (like spots) to make sure you get no blocking sound.  With some health you can endure hits from the frog while positioning if necessary.  I do not think the blocking sound otherwise affects the speed of the kill.

Due to the RNG of the jumps, I have so far been unable to find a character starting position at the top of the room where you can stay and have your grenade shot always connect when the frogs open their mouths.  Staying at the same X position as when you enter the room on Boss 7 seems to land the frog in position somewhere in the range of 75-90% of the time.  (It would perhaps take a great deal of testing I probably don't want to do trying to locate a position that is 100%, and there likely isn't one.)  I have found that always adjusting your character's position just before the grenade glitch tends to get the best results.  It can also help to get into position quickly for the grenade glitch, and spam grenades (I do not think this can add lag unless you are mashing incredibly quickly).

Example Area 7 Boss Strategy - Enter and quickly move upward to the back of the room.  At some point, quickly face downward and hold A to hold downward facing.  Use pixels on the wall or floor and/or pixels on the frog to get 5 to 7 pixels from the top of the room.  As the frog jumps, shuffle left and right staying centered on the frog, and counting the jump landings.  On the 4th landing, line up with the mouth and fire a grenade into a pause glitch (be familiar with the timing of these).

Example Area 4 Boss Strategy - Same strategy as Area 7 boss, but you get to the back wall quicker, and can use the wall or floor more for positioning.  If you don't have health to spare, stand to the side of the frog until its first jump.  On the 3rd landing, line up and fire a grenade then pause.

You must be careful not to pause while being hit as this will quickly drain your life.  Also be careful about moving quickly onto the frog's body after it dies as its hurtbox can be active for some frames after it dies.

Demonstration video of Boss 7 - https://youtu.be/zgLeQIVPraw
Images showing 5 and 7 pixel positions on Boss 4 to prevent grenade glitch noise - http://i.imgur.com/gLJCX7q.png
Images showing 5 and 7 pixel positions on Boss 7 to prevent grenade glitch noise - http://i.imgur.com/I12bycO.png

Something else I have noticed is it takes something like 15 to 40 frames from when the boss is dead to when the damage sound changes to the kill sound.  You can actually save time by timing the unpause of the grenade glitch instead of listening for when to do so, though this would be difficult to do well.

Credits
Pause Grenade Glitch - one of the oldest and most well-known video game glitch discoveries