f add more color to what's going on

Author: TheBlueMatt

lightning/src/routing/scoring.rs

@@ -1747,8 +1747,9 @@ mod bucketed_history {
 			&self, now: T, last_updated: T, half_life: Duration, amount_msat: u64, capacity_msat: u64)
 		-> Option<u64> {
 			// If historical penalties are enabled, calculate the penalty by walking the set of
-			// historical liquidity bucket (min, max) combinations (where min_idx < max_idx) and, for
-			// each, calculate the probability of success given our payment amount, then total the
+			// historical liquidity bucket (min, max) combinations (where min_idx < max_idx, as
+			// having a minimum above our maximum is an invalid state). For each combination,
+			// calculate the probability of success given our payment amount, then total the
 			// weighted average probability of success.
 			let mut total_valid_points_tracked = 0;