Replay Expressions

This reference covers the native video player and the counters and custom events on the video analysis page. It does not apply to third-party players. All three use expr-eval syntax, but their fields and result requirements differ.

Three Contexts

Feature	Video player	Analyzer counter	Analyzer custom event
Location	Custom counter in the native player dialog	Numeric counter on the analysis page; data tracks reference its results	Custom event rows on the analysis page
Input	Replay getters at the current playback position	Native event snapshots and static replay data	The same fields as analyzer counters
Final result	Converted to text; numbers and strings can be concatenated	Must be a single number; NaN and positive/negative infinity are allowed	Must be a boolean, number or string
Evaluation	When playback position updates	At samples selected by each row's sampling mode	Continuous sampling: the last native event in each millisecond
Between samples	Does not use analyzer sample interpolation	Linear interpolation over time; outside the sample range, holds the nearest endpoint	Uses sampled occurrence states, not interpolated truth values
Display format	roundTo, string concatenation, etc. inside the expression	Separate d3-format format input, default .3f	Color and marker/line styles; no numeric format
Errors	Displays the error text	Displays the error in the value cell	Parse/evaluation errors or invalid result types mean the event does not occur
Difference function d	Not supported	Supported; predecessors follow the row's sampling mode	Supported; predecessors follow continuous sampling

Custom events use native JavaScript truthiness: true, nonzero numbers and nonempty strings mean occurrence; false, 0, -0, NaN and empty strings mean no occurrence. Positive/negative infinity mean occurrence. "false", "0" and whitespace-only strings also mean occurrence. Other types, including arrays and functions, mean no occurrence.

Continuous sampling includes all native event types and samples every millisecond. It uses the last event in that millisecond, or all fields of the latest preceding native event when there is no event, including time. The sample timestamp advances, but time keeps the source event's original time. Counter button/board-change modes filter eligible events first, then keep the last eligible event in each millisecond without filling gaps. Counter row sampling settings do not affect custom events.

The timeline and board use the same event hover details: pulses show their time and the numeric or string expression result, omitting boolean values; sustained events show their full start time, end time and duration, even when the visible range clips them. Times are displayed in seconds with three decimal places.

The custom-event “Board marker size” setting affects only the board layer. Timeline markers stay at 8px and retain the event shape, color and opacity.

New configurations enable the board custom-event layer with pluck selected. Hover over a pulse marker to see its time and value (omitting booleans), or over a sustained-event trace to see its full start time, end time and duration, even when only part of the trace is shown. Saved layer settings are preserved.

Supported Fields

“Yes” means the name is available directly as an expression variable; “—” means it is not. Names are case-sensitive. Analyzer dynamic values come from sampled events; static values describe the entire replay. The player reads its current getters without substituting 0. Names outside these tables, including currentMs, current_time, timeMs and bvs, are not supported. Counter row keys and event keys are not variables in other expressions.

Static Board and Replay Fields

Field	Meaning and unit	Video player	Analyzer counter	Custom event
row	Board row count	Yes	Yes	Yes
column	Board column count	Yes	Yes	Yes
mine_num	Total mine count	Yes	Yes	Yes
pix_size	Original replay cell size in pixels, not the displayed size	Yes	Yes	Yes
bbbv	3BV of the entire board	Yes	Yes	Yes
op	Opening count of the entire board	Yes	Yes	Yes
isl	Island count of the entire board	Yes	Yes	Yes
cell0	Number of zero (blank) cells on the entire board	Yes	Yes	Yes
cell1	Number of cells showing 1 on the entire board	Yes	Yes	Yes
cell2	Number of cells showing 2 on the entire board	Yes	Yes	Yes
cell3	Number of cells showing 3 on the entire board	Yes	Yes	Yes
cell4	Number of cells showing 4 on the entire board	Yes	Yes	Yes
cell5	Number of cells showing 5 on the entire board	Yes	Yes	Yes
cell6	Number of cells showing 6 on the entire board	Yes	Yes	Yes
cell7	Number of cells showing 7 on the entire board	Yes	Yes	Yes
cell8	Number of cells showing 8 on the entire board	Yes	Yes	Yes
zini	Flagging operation count estimated by a greedy algorithm (ZiNi)	Yes	Yes	Yes
hzini	Operation count after opening all openings first, then applying the greedy algorithm (Human ZiNi)	Yes	Yes	Yes
rtime	Total replay duration in seconds, not current playback progress	Yes	Yes	Yes
level	Replay difficulty level code	Yes	Yes	Yes
mode	Replay game mode code	Yes	Yes	Yes

cell0 through cell8 are nine separate variables. cell0-8 is not a variable name.

Dynamic and Player-Only Fields

Field	Meaning and unit	Video player	Analyzer counter	Custom event
time	Original sampled event time in seconds; may be negative before the game timer starts and differs from page playback progress	—	Yes	Yes
path	Cumulative mouse path length, retaining the library's value regardless of displayed cell size	Yes	Yes	Yes
bbbv_solved	3BV solved so far	Yes	Yes	Yes
left	Cumulative left clicks	Yes	Yes	Yes
right	Cumulative right clicks	Yes	Yes	Yes
double	Cumulative double clicks	Yes	Yes	Yes
lce	Cumulative effective left clicks	Yes	Yes	Yes
rce	Cumulative effective right clicks	Yes	Yes	Yes
dce	Cumulative effective double clicks	Yes	Yes	Yes
flag	Flag count	Yes	Yes	Yes
op_solved	Openings opened so far	—	Yes	Yes
isl_solved	Islands solved so far	—	Yes	Yes
mouse_state	Mouse state code; analyzer samples use the state after the native event	Yes	Yes	Yes
bbbv_s	3BV per second	Yes	—	—
ce	Total effective clicks	Yes	—	—
ce_s	Effective clicks per second	Yes	—	—
cl	Total clicks	Yes	—	—
cl_s	Clicks per second	Yes	—	—
left_s	Left clicks per second	Yes	—	—
right_s	Right clicks per second	Yes	—	—
double_s	Double clicks per second	Yes	—	—
flag_s	Flagging rate	Yes	—	—
etime	Estimated completion time in seconds	Yes	—	—
rtime_ms	Total replay duration in milliseconds	Yes	—	—
rqp	RQP speed metric	Yes	—	—
stnb	STNB completion and speed metric	Yes	—	—
corr	Operation accuracy metric	Yes	—	—
thrp	Throughput efficiency metric	Yes	—	—
ioe	Index of efficiency	Yes	—	—
pluck	Cumulative Pluck metric	Yes	Yes	Yes
current_event_id	Current native event array index, not a time value	Yes	—	—
game_board_state	Game board state code	Yes	—	—
video_start_time	Replay start time offset in seconds	Yes	—	—
video_end_time	Replay end time coordinate in seconds	Yes	—	—

The analyzer does not expose bbbv_s, cl or ce directly. You can combine supported fields, for example bbbv_solved / time, left + right + double or lce + rce + dce. Such formulas are not guaranteed to match player getter algorithms in every special state.

The Analyzer computes per-event pluck when loading a replay. Raw values are preserved: unavailable values may be NaN, and the mine-hit failure value is Number.MAX_VALUE, without replacement by zero or infinity.

mouse_state Codes

Value	State	Meaning
1	UpUp	Both left and right buttons released
2	UpDown	Left released, right pressed
3	UpDownNotFlag	Left released, right pressed without placing or removing a flag
4	DownUp	Left pressed, right released
5	Chording	Both buttons pressed
6	ChordingNotFlag	Both pressed after pressing the right button first on a cell that cannot be right-clicked
7	DownUpAfterChording	Right released first after chording, left still pressed
8	Undefined	Uninitialized state

Names such as DownUp are not expression constants. Use their numeric codes, for example mouse_state == 4.

Operators and Syntax

All three contexts support the following operations, but a counter's final result must still be numeric. Arrays, strings and booleans may be intermediate results. The table roughly follows precedence from highest to lowest; use parentheses when unsure.

Operator or syntax	Meaning and example	Video player	Analyzer counter	Custom event
(...)	Grouping, e.g. (left + right) / time	Yes	Yes	Yes
f(...), a[i], x.y	Function call, zero-based indexing and property access, e.g. [left, right][0] or [left, right].length; does not bypass the variable whitelist	Yes	Yes	Yes
[a, b, ...], "text", 'text'	Array and string literals	Yes	Yes	Yes
x!	Postfix factorial: 5! is 120, not logical NOT	Yes	Yes	Yes
x ^ y	Exponentiation: 2 ^ 3 is 8, not XOR	Yes	Yes	Yes
+x, -x, not x	Numeric conversion, negation and logical NOT; unary math functions are listed below	Yes	Yes	Yes
*, /, %	Multiplication, division and remainder	Yes	Yes	Yes
+, -	Numeric addition and subtraction; + is not string concatenation	Yes	Yes	Yes
x || y	String concatenation, or array concatenation when both operands are arrays; not logical OR	Yes	Yes	Yes
==, !=, <, <=, >, >=	Comparisons, e.g. left > right	Yes	Yes	Yes
x in a	Array membership, e.g. mouse_state in [4, 5, 7]	Yes	Yes	Yes
x and y	Logical AND; skips the right operand if the left is false	Yes	Yes	Yes
x or y	Logical OR; skips the right operand if the left is true	Yes	Yes	Yes
c ? a : b	Conditional expression; only evaluates the selected branch; nesting allowed	Yes	Yes	Yes
a; b	Evaluates in sequence and returns the last result; not a variable declaration	Yes	Yes	Yes
x = value	Assignment	No	No	No
f(x) = expr	Function definition	No	No	No
if (...) { ... }, &&, !x, **, ===, =>	JavaScript statements/operators or arrow functions; not this expression grammar	No	No	No

Use the keywords and, or and not. Logical results are booleans; use condition ? 1 : 0 for a numeric counter result. Scientific notation such as 1e-3 is supported. Prefer parentheses around unary function arguments, e.g. sin(time)^2, to avoid precedence ambiguity.

Constants

Constant or expression	Meaning	All three contexts
PI	Pi	Supported
E	Euler's number	Supported
true, false	Booleans	Supported, but not valid final counter results
0 / 0	Produces NaN	Supported; retained as a counter number, false for custom events
1 / 0, -1 / 0	Produces positive/negative infinity	Supported; retained as counter numbers, true for custom events
NaN, Infinity, Inf, null, undefined	These names are not built-in constants	Not supported

Functions

These built-in functions and function-form unary operators are supported in all three contexts. x, a and f are argument placeholders, not extra replay fields. Angles are in radians.

Function	Meaning and example	Video player	Analyzer counter	Custom event
abs(x)	Absolute value, e.g. abs(-3)	Yes	Yes	Yes
sign(x)	Sign; negative/zero/positive numbers normally produce -1/0/1	Yes	Yes	Yes
ceil(x)	Round up	Yes	Yes	Yes
floor(x)	Round down	Yes	Yes	Yes
round(x)	Round to the nearest integer using JavaScript rounding rules	Yes	Yes	Yes
trunc(x)	Remove the fractional part towards zero	Yes	Yes	Yes
roundTo(x, n)	Round to n decimal places, e.g. roundTo(time, 3); negative n rounds to tens, hundreds, etc.; does not pad trailing zeros	Yes	Yes	Yes
min(a, b, ...)	Minimum; also accepts an array, e.g. min([left, right])	Yes	Yes	Yes
max(a, b, ...)	Maximum; also accepts an array, e.g. max([left, right])	Yes	Yes	Yes
sqrt(x)	Square root	Yes	Yes	Yes
cbrt(x)	Cube root	Yes	Yes	Yes
pow(x, y)	Exponentiation, equivalent to x ^ y	Yes	Yes	Yes
hypot(a, b, ...)	Square root of the sum of squared arguments	Yes	Yes	Yes
pyt(a, b, ...)	Alias for hypot	Yes	Yes	Yes
exp(x)	E ^ x	Yes	Yes	Yes
expm1(x)	exp(x) - 1	Yes	Yes	Yes
ln(x)	Natural logarithm	Yes	Yes	Yes
log(x)	Alias for ln; not base 10	Yes	Yes	Yes
log2(x)	Base-2 logarithm	Yes	Yes	Yes
log10(x)	Base-10 logarithm	Yes	Yes	Yes
lg(x)	Alias for log10	Yes	Yes	Yes
log1p(x)	ln(1 + x)	Yes	Yes	Yes
sin(x)	Sine	Yes	Yes	Yes
cos(x)	Cosine	Yes	Yes	Yes
tan(x)	Tangent	Yes	Yes	Yes
asin(x)	Inverse sine	Yes	Yes	Yes
acos(x)	Inverse cosine	Yes	Yes	Yes
atan(x)	Inverse tangent	Yes	Yes	Yes
atan2(y, x)	Direction angle of vector (x, y); y comes first	Yes	Yes	Yes
sinh(x)	Hyperbolic sine	Yes	Yes	Yes
cosh(x)	Hyperbolic cosine	Yes	Yes	Yes
tanh(x)	Hyperbolic tangent	Yes	Yes	Yes
asinh(x)	Inverse hyperbolic sine	Yes	Yes	Yes
acosh(x)	Inverse hyperbolic cosine	Yes	Yes	Yes
atanh(x)	Inverse hyperbolic tangent	Yes	Yes	Yes
gamma(x)	Gamma function; for positive integer n, gamma(n) = (n - 1)!	Yes	Yes	Yes
fac(x)	Factorial, corresponding to x!; non-integers use the Gamma extension	Yes	Yes	Yes
random(n)	Random number in [0, n); uses 1 if n is omitted or zero; unsuitable for reproducible analysis	Yes	Yes	Yes
length(x)	String or array length	Yes	Yes	Yes
indexOf(x, a)	First zero-based index of x in string or array a; -1 if absent	Yes	Yes	Yes
join(sep, a)	Join array elements into a string using separator sep	Yes	Yes	Yes
map(f, a)	Apply a function to array elements and return an array, e.g. map(abs, [-1, 2])	Yes	Yes	Yes
filter(f, a)	Keep elements whose function result is truthy; returns an array, e.g. filter(abs, [-1, 0, 2])	Yes	Yes	Yes
fold(f, initial, a)	Reduce an array to one value, e.g. fold(pow, 2, [3, 2]) produces 64	Yes	Yes	Yes
if(c, a, b)	Select a or b based on c, but evaluates both arguments first; use c ? a : b for short-circuiting	Yes	Yes	Yes
not(x)	Logical NOT, also written not x; returns a boolean	Yes	Yes	Yes
d(expr)	Numeric expression at the current sample minus its value at the preceding sample	—	Yes	Yes
d(expr, n)	Subtract the value n samples earlier; n must be a positive integer	—	Yes	Yes

Function arguments to map, filter and fold may use compatible built-ins, not JavaScript arrow functions or new function definitions. There are no general String, Number, isNaN, isFinite or Math.* functions. Use unary + for numeric conversion, "" || value for text concatenation and value != value to test for NaN, replacing value with an actual field or expression. d requires a direct call and cannot be used as an array-function callback.

Difference Rules

Rule	Explanation
Operand	A field or numeric expression, e.g. d(left), d(left + right) or d(bbbv_solved) / d(time)
Default step	d(expr) equals d(expr, 1); counts retained samples, not milliseconds or native event count
Step expression	n is evaluated at the current sample, e.g. d(left, time > 1 ? 2 : 1); nonpositive/noninteger steps are errors
Missing predecessors	Returns NaN; counters retain it, custom events treat it as no occurrence
Nesting	d(d(left)) and d(d(left, 2), 3) work; their first two and five samples respectively are NaN
No automatic normalization	Does not divide by the step or elapsed time; explicitly divide by d(time) for a rate
Evaluation order	Filter and deduplicate millisecond samples, then evaluate differences; counter interpolation and formatting happen afterwards
Conditional branches	Skipping a difference call does not change which sample is the predecessor

Default Counters

On first use, the counters use continuous sampling and the .3f display format:

key	Expression	Default Plot
Bvs	d(bbbv_solved, 1000) / d(time, 1000)	Plot 1
Ces	d(lce+rce+dce, 1000)/d(time, 1000)	Plot 1
Mov	d(path, 1000) / d(time, 1000) / 16	Plot 2

Here, 1000 counts continuous millisecond samples; the denominator uses the difference in the original event's time. The first 1000 samples are NaN, and a zero time difference can also produce non-finite values. The lowercase bvs is no longer a default counter. Saved counter and Plot configurations are preserved.

Default Custom Events

On first use, the following events are included:

key	Type	Expression
left	Sustained	mouse_state in [4, 5, 6, 7]
right	Sustained	mouse_state in [2, 3, 5, 6]
pluck	Pulse	d(pluck)

The pluck pulse occurs when the cumulative value changes from the previous millisecond. An unchanged value or a NaN difference produces no pulse. Existing saved custom events are preserved.

Examples

Context	Expression	Result
Video player	roundTo(bbbv_s, 3) || "@" || bbbv_solved || "/" || bbbv	Combine rate, solved BV and total BV as text
Analyzer counter	time > 0 ? bbbv_solved / time : 0	Cumulative 3BV/s; the separate format can be .3f
Analyzer counter	d(bbbv_solved) / d(time)	3BV/s between samples; first sample is NaN
Pulse custom event	d(left) > 0	A pulse when cumulative left clicks increase
Sustained custom event	mouse_state in [4, 5, 6, 7]	Continuous segments where the left button is pressed
Custom event	mouse_state == 4 and d(left) > 0	Require both a mouse state and a click increase

Syntax reference: expr-eval. Separate counter display formatting: d3-format; format is not an expression function.