From 14ffc2f9a24395905fd9ef9a8ad70b31f3683a7b Mon Sep 17 00:00:00 2001
From: dan63047 <44553627+dan63047@users.noreply.github.com>
Date: Thu, 21 Sep 2023 19:50:39 +0000
Subject: [PATCH] Some things about basic stats

---
 Meaning-and-the-essence-of-stats.md | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/Meaning-and-the-essence-of-stats.md b/Meaning-and-the-essence-of-stats.md
index 2a9035b..61fcefb 100644
--- a/Meaning-and-the-essence-of-stats.md
+++ b/Meaning-and-the-essence-of-stats.md
@@ -14,11 +14,19 @@ Whole GLICKO-2 rating system is a method of assessing a player's strength in com
 
 GLICKO-2 system also has a system constant, responsible for "change in volatility over time". So, yeah, each player has hidden variable, called "volatility", which is high if you successfully compete against higher rated players (or vise versa), and low if you play "on your rating". The value of constant, hoverer, unknown.
 #### [RD] Rating deviation
-Ok it's not a Reliability Deviation.
+That number tells, how the rating system uncertain about player rating. It goes down every played match on some amount, that calculated very weirdly and goes up by 1 each day after week of inactivity (if RD less, than 350). RD also has a soft floor of 60 RD, but it's possible to get lower RD by playing big amount of games. If your RD higher, than 100, your rank gets hidden. 
 #### [WR] Win Rate
+Very very old and inaccurate way to determine players skill. It's just a ratio of wins to played games.
 #### [APM] Attack per Minute
+That one is easy to understand. It's just a ratio of attack (sent + cancelled lines) to time (minutes). The only problem is — it's still may be not accurate, since you can send 20 attack in 5 seconds with opener and then have no skill to play midgame, having in total, let's say, 120 APM, or just play good midgame without opener and be really strong opponent with same 120 APM.
 #### [PPS] Pieces per Second
+That's also easy. It's a measurement of speed. It's just a ratio of placed pieces to time (seconds). The faster you place pieces, the bigger it is.
 #### [VS] Versus Score
+That metric was invented by osk and promoted in game, as "general indicator of skill". It calculated with this formula: 
+
+`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.
 ### Calculated by using fancy math
 #### [APP] Attack per Piece
 #### [VS/APM] Versus Score per Attack per Minute