After completing the first part of the lemma research - penalty box - the second part was shorter, easier, but just as useful. I decided to find out the share of time teams spend on average while at even strength, on power play/shorthanded and with empty net. Then given this number, and the number of goals scored in each such situation, I was able to calculate the frequency of EVG/PPG/SHG/ENG or the reverse of it which I called the difficult of such goal.

 

I scanned the database of all games between the 1999/00 season and today, and all the goals extracted from these games. Penalty shot goals were ignored, regardless if during the game itself, or in post-game shootout. The EN time was calculated as total game time minus goaltender TOI. PP/SH time was deducted from the recorded PP TOI of the players. The EV time would naturally become the total game time minus EN minus PP of both teams.

 

Then I calculated the difficulty of scoring a goal in each of these situations through the following formula:

 

Season	EV	PP	SH	EN
1999	1.000	0.502	3.506	0.162
2000	1.000	0.473	3.387	0.146
2001	1.000	0.492	3.635	0.153
2002	1.000	0.468	3.585	0.167
2003	1.000	0.445	3.127	0.221
2005	1.000	0.535	4.247	0.272
2006	1.000	0.506	4.000	0.228
2007	1.000	0.458	3.597	0.187
2008	1.000	0.438	3.745	0.183
2009	1.000	0.456	4.044	0.192
2010	1.000	0.450	3.517	0.177
2011	1.000	0.460	3.568	0.169
2012	1.000	0.430	3.890	0.169
2013	1.000	0.453	3.209	0.198
2014	1.000	0.427	3.564	0.171
2015	1.000	0.415	3.284	0.158
2016	1.000	0.419	3.252	0.178
2017	1.000	0.427	3.052	0.168

 

The dataset containing this data is available on the website, on the Request Analysis page.

 

So why did I need these two lemmas? That blog post won't be ready any time soon, and I better resume the "Page A Day series'.