Thinking about DS/S

Meaning-and-the-essence-of-stats.md

@@ -43,7 +43,7 @@ That metric was invented by osk and promoted in game, as "general indicator of s
 
 `VS = [ ( attack + garbage lines cleared ) / pieces ] * PPS * 100`, where constant of 100 here is just for scale. 
 
-That metric encourages player for using garbage lines.
+That metric encourages player for using garbage lines in attacks, as well, as playing efficiently.
 
 ### Calculated by using fancy math
 
@@ -58,6 +58,14 @@ That's a ratio of attack to number of placed pieces. Basically, an efficiency me
 That's a ratio of versus score to attack per minute.
 
 #### [DS/S] Downstack per Second
+
+That metric shows, how fast you clearing lines
+
+`DS/S = (VS / 100) - (APM / 60)`
+
+
+`DS/S = [ ( attack + garbage lines cleared ) / pieces ] * PPS - APS`, where APS is attack per second
+
 #### [DS/P] Downstack per Piece
 #### [APP + DS/P] Summary of Attack per Piece and Downstack per Piece
 #### [Cheese] Cheese Index