Checker is the 42nd Expert floor in Monkey Ball and Super Monkey Ball and the 81st Expert stage in Super Monkey Ball Deluxe. It also appears as the 191st Ultimate stage with continues and the 231st without continues.
This stage has a lot of diagonals. It has a blue goal, a green goal, and a red goal. It is considered incredibly difficult unless you know where exactly to go. For the blue goal, you turn to the left and keep a consistent diagonal maneuver, which is hard enough. For the green goal, you turn to the right and make more minor adjustments, which is even harder. For the red goal, this is easily the hardest to conquer. You have to go behind the goals and go on more than two times as many diagonals as before with many adjustments. It also offers a lot of bananas.
The use of pause buffering can save your life in this level. There are three possible timings to reach the red goal and one emergency timing to take a shortcut to the green goal path in case you miss all three chances, so you don't fall out and die. Follow these instructions if you want to reach the red goal fast and consistently. You only need strict timing.
Hold Up+Right on your Analog Stick as soon as the level starts. Then you want to pause between 59:68-59:70 while still holding Up+Right. Then if you got the right timing, change your direction to Up+Left and unpause. This will guarantee a bounce long enough to reach the square next to the red goal. Now, pay attention because the inputs after unpausing at 59:68 or 59:70 are different.
If you paused at 59:68, you must hold Up+Right between or after 58:70-58:75, which is the moment you collide with the square next to the red goal.
Otherwise, if you paused at 59:70 you must hold Up between or after 58:60-58:65, that timing is the moment you hit the next square close to the red goal.
If you failed to input the pause in both times but you achieved to pause at 59:66, there is one last thing you can try, hold Down+Left, unpause, and pause again at 59:63, then hold Up+Left and this last input should lead you automatically to the red goal without more adjustments.
If you failed that again but you managed to pause from 59:66 to 59:61, just proceed with Up+Left, but you will need to input Up+Right after your last jump from the square to the red goal.
Emergency Pause Buffer
If all of the above failed but you paused from the start of the level to 59:63, you won't get any red goal and you will mostly die, but you can save your monkey by holding Up+Left and hit one of the squares, then keep holding the same direction or change Up+Right when you land in the square, and carefully pause buffer your inputs until you manage to balance the monkey without falling off the floor. This can be done at any point of the level with diagonal pathways whenever you feel you will fall out but still are on the floor. As long as you don't fall out, you can recover the balance of your monkey with this emergency method.