#5 close-up: bounces 54→57, every step

Start
mid-run: step 12,287 (bounce 54), reached by simulating from the blank tape
Rows
every step (1 row = 1 step, drawn 2 px tall): steps 12,287–12,992
Window
cells −76..59 = the whole visited tape; 1 cell drawn 5 px wide
Colors
1   0 (or never visited)   head: just moved right, just moved left
Marks
| blue line = left end of the block at the last bounce; ○ = wave turns at 00
Style
bbchallenge default colors (plus blue annotations)
space-time diagram −70−60−50−40−30−20−1001020304050celledge w = cells −73..17 (91 cells)block 135edge w = cells −73..17 (91 cells)block 138step 12,287step 12,99212,35012,40012,45012,55012,60012,65012,70012,75012,80012,85012,90012,950bounce 54step 12,287bounce 55step 12,492bounce 56step 12,681bounce 57step 12,992
Bounce k = the k-th time A reads the 0 just past the right end. Block length after a trip: nnext = n + 1 − (cells eaten). Over 32,262 bounces to step 109 the edge eats 0.058 cells per trip on average (range −1..+11).