Minecraft – “hitting the ground too hard?” in Minecraft

Debug numbers

• C is the number of renderers* being rendered over total number loaded
• F is number of renderers being clipped (i.e. not viewable)
• O is the number of renderers removed through occlusion culling
• E (first line) is the number of renderers skipped
• E (second line) is the number of rendered entities over total entities
• B is the number of entities hidden
• I is the number of individually removed entities (the remainder of B and the numerator of E combined)
• P is the number of particles
• T: All is the total number of entities
• MultiplayerChunkCache is the number of chunks currently loaded into memory

• x and z are your current coordinates along the horizontal plane
• y (feet pos) is the current coordinate along the vertical plane of the floor you're walking on
• y (eyes pos) is the current coordinate along the vertical plane of your eye level (Steve's eyes being 1.620 blocks above the ground)
• f is the orientation of Steve: 0 is west, 1 is north, 2 is east, 3 is south
• lc is the height level of the highest non-air block within the current chunk
• b is the name of the biome you're currently in
• bl is the light level of the block your head is in, from block-based lights like torches
• sl is the level of sunlight/moonlight on the block your head is in (independent of the current time of day)
• rl is the maximum of bl and sl
• ws is your walk speed
• fs is your flying speed
• g is whether your feet are on the ground (true if you are, false otherwise)

Graphs

The bar graph charts frame rate over time inversely (e.g., higher spikes = lower frame rate). Green plots are when your frame rate is 60 FPS or higher.

The pie graph charts the distribution of CPU time across different parts of Minecraft:

• [0] root (white) is essentially a sanity check: should always be 100%
• [? probably 1]unspecified (green) is the time spent on things not already enumerated
• [2] render (blue) is the time spent on rendering the world
• [3] tick (purple) is the time spent on the game clock (heartbeat)
• [4] sound (yellow) is the time spent on the sound engine
• [5] updatelights (salmon) is the time spent on updating the lighting engine (usually at sunset and sunrise)

Pressing the 1-9 keys will show sub-divisions of the numbered slices of the pie chart (in addition to switching items as usual), and pressing 0 will go back up.

Notes

• A chunk, if you're not familiar with the term, is a section of the world, equal to 16x128x16 blocks.
• Given the context in which it appears in RenderGlobal.java, I believe "renderers" refers to a single block.
• Under the Minecraft coordinate system, X and Z are the horizontal axes and Y is the vertical axis, which confuses players used to other coordinate systems.

I'm assuming you run the server. You could:

• Op yourself and disable spawn protection, then mine out the area.
• Use a plugin to set the spawn point (I'd suggest EssentialsSpawn)
• Load the map into MCEdit and move the spawn point up a couple of blocks.

If you don't run the server, see if you can set yourself a /home position.