                  2020:  A most interesting season 

This is being written as we wrap up the 2020 season database and the Diamond 
Mind Baseball (DMB) version 12 upgrade, and it's hard to overstate the 
profound impact that this unusual season had on our work on both projects. 

Four databases, three schedules, two goals
------------------------------------------ 

As you probably know by now, we chose to create four editions of the 2020 
season database, two in DMB 11 format and two in DMB 12 format.  For each 
version, there's a 60-game edition and a 162-game edition. 

All four editions include three schedules.  There's the original 162-game 
schedule that was published last winter before anyone knew the impact of the 
coronavirus pandemic.  There's the original 60-game schedule that was 
announced before play began in July.  And the 60-game schedule that indicates 
when the games were actually played.
 
On the two original schedules, all games are set up for nine innings.  On the 
as-played 60-game schedule, the version 11 edition also has all games as nine 
inning affairs, but the version 12 edition has 7-inning games to match those 
in real life.
 
By the way, there was one double header in the first week of the season where 
both games were nine innings.  Only after that did the league decide to go 
with seven innings for double headers for the rest of the season.
 
We chose this approach to support two fundamentally different ways of 
playing.
 
First, the 60-game editions include the actual 2020 stats and splits, rosters 
set up for opening day, and a full set of real-life transactions and game-by-
game starting lineups so you can carry out a detailed replay of the 2020 
campaign.
 
Second, the 162-game editions are intended mainly for use in draft leagues.  
All player and team stats and splits have been prorated to 162 games so they 
resemble the full-season stats you're accustomed to seeing.  The thresholds 
for playing time penalties have been prorated accordingly.  The rosters are 
set up with the most-used players activated.  And the real-life transactions 
and lineups have been removed.
 
By the way, any time stats are prorated like this, rounding can cause team 
totals to differ very slightly from certain norms.  For example, if you look 
at the games started report for a team, you'll see that some positions might 
total 163 starts and some 161, instead of the usual 162 for all positions. 

As an example, suppose a team had one player who made 57 starts and three 
other players who made one start each at a position.  In the 60-game edition, 
their starts total 60, as expected.  When prorated to 162 games, their starts 
work out to 154, 3, 3, and 3, for a total of 163.  There's nothing wrong with 
the data ... it's just rounding.
 
We held this truth to be self-evident, that ...
-----------------------------------------------

... all big-league games are created equal, and shall consist of exactly nine 
innings, unless the two teams shall be tied after nine full innings, in which 
case ...
 
It was no trivial matter to update DMB to support seven-inning games.
 
We started by enhancing the DMB schedule editor, schedule templates, schedule 
import/export tools, schedule reports, and game results reports to handle 
seven-inning games.  Actually, if you feel the urge, you can create games of 
any length from five to nine innings.  And store them as schedule templates 
for future use.
 
In the schedule editing window, the scheduled game window, and the reports, 
we don't display the innings for plain old nine-inning games.  No need to 
clutter up the screen or the page with lots of 9s when that game length has 
been a given for a century and a half. 

Before a game is played, you'll see the number of innings if it's something 
other than 9.  After a game is played, you'll still see it for those games 
and also for games that went to extra innings.  The only time you'll see a 9 
is when the game was scheduled to be shorter but went into extra innings and 
then ended in the 9th. 

We updated the scoreboard on the main game window and the various places 
where linescores appear -- boxscores, scoresheets, and game logs -- to 
display the right number of innings.
 
More importantly, we taught the computer manager to handle the shorter 
games.  You'll see closers entering in the seventh, setup relievers and pinch 
hitters in the 5th and 6th, defensive replacements in the 6th and 7th, and 
other tactics being used earlier.
 
The simplest way to think about it is to count innings from the back of the 
game instead of the front.  Moves that should be considered with three 
innings left are still considered with three innings left.  It's just that 
the third-last inning is the fifth inning of a seven-inning game.
 
It's not quite that simple, of course.  In a nine-inning game, you might use 
a setup reliever in the 8th because you want to or because the starter has 
thrown 107 pitches and it's time to get him out of there anyway.  Going into 
the sixth inning of a seven-inning game, you might still have good reason to 
go to the pen, but it's likely the starter has only thrown 80 pitches, so 
sticking with him is a viable option, too.
 
The seven-inning games also had an affect on how we rated players for the 
2020 season database.
 
Our Clutch and Jam ratings are determined based on performance in the late 
innings of close games.  The widely accepted definition of late innings is 
the seventh inning or later, but that doesn't make sense in a seven-inning 
game.
 
So we updated our program that computes clutch stats to be more flexible 
about when it's "late".  At the time, we did a little checking and found that 
it's unclear whether the major web sites that display late/close stats are 
going to stick with the old definition or update it for these shorter 
contests.
 
There's a bit of a statistical impact, too, though it's not a big deal.  If 
you replay the 2020 season using DMB 11, which does not support seven-inning 
games, you'll see roughly 400 more innings played in your DMB season than in 
the real 2020 season.  That's only about a 3% increase, but it will have a 
small effect on the amount of playing time each player gets.
 
Of course, if you replay the 2020 season with DMB 12, there will be almost no 
difference in playing time between the real season and your DMB season.
 
Once is not enough
------------------
 
It is no longer true that a pitcher can be replaced after facing only one 
batter or ending an inning by picking off a runner, nabbing a base stealer, 
or getting an out on the bases in some other way.
 
DMB 12 gives you the option to require a pitcher to face three batters (or 
retire the side) before being removed.  You can continue to set up your 
leagues to use the traditional one-batter minimum, of course.  But if you 
choose to use the new rule, be aware of a subtle case that we didn't know 
about when the new rule was first announced.
 
Suppose you bring in a reliever with two outs in an inning and he retires his 
first batter for the third out.  You can replace him before the next inning 
starts.  But if you choose to bring him back out, you'll have to leave him in 
for two more batters.  The three-batter minimum is back in effect if you 
forgo your opportunity to lift him between innings.
 
I wanna go home
---------------
 
Extra innings had a new look this year.  Each half inning began with a runner 
on second base.  The rule specifies that this automatic runner is the player 
one spot behind the inning's leadoff hitter in the batting order.  But if 
that lineup slot is occupied by the pitcher, the slot is skipped and the next-
previous batter takes second. 

If you replay the 2020 season using DMB 11, these automatic runners will not 
be used.  As a result, there won't be as many runs scored in extra innings in 
your DMB games as there were in real life.
 
But if you use DMB 12 for your season replay, these runners will be placed, 
and there will be no significant difference in scoring between the real 
season and DMB. 

By the way, if you're used to a certain ratio of earned runs to total runs, 
you'll need to recalibrate for 2020.  All runs scored by these automatic 
runners are unearned, and as you can imagine, quite a few more runs are 
scored when innings begin with a runner in scoring position.
 
You get a DH, you get a DH, you get a DH
----------------------------------------

This was the first season in which the Designated Hitter was used in both 
leagues. 

For a normal season during the DH era, we would create manager profiles 
consisting of four saved lineups:  one for each combination of left/right and 
DH/non-DH.  For our 2020 season database, we're providing two saved lineups 
per team, one each for left- and right-handed opposing pitchers in DH games.
 
There's no place like home
-------------------------- 

Another aspect of the 2020 season that had many effects was the large number 
of games played somewhere other than the home team's park. 

Because Canada closed its border with the US during the pandemic, Toronto was 
forced to find a new home.  They eventually settled on Sahlen Field in 
Buffalo, which became one of two new parks for 2020.  The other was Globe 
Life Field, which replaced Globe Life Park in Texas, finally clearing up the 
age-old debate about whether a field is better than a park.
 
DMB 12 users will find new park images for these debut parks and updated 
images for Oracle Park and Marlins Park, both of which pulled in sections of 
their outfield fences by a few feet.
 
That was the easy part.  The real work began when it came time to calculate 
park factors for 2020.
 
The first challenge was the large number of games moved to alternate venues.  
Suddenly there was a disconnect between which team is officially the home 
team for a game (and bats second) and which team was actually hosting the 
game in their stadium.
 
Baltimore played 34 games at home and 26 on the road, even though they were 
officially the home team for the expected 30 games out of 60.  Seattle, on 
the other hand, had only 24 games in Safeco Park and 36 in other stadiums.  
Only 8 teams played exactly 30 games in their home parks.
 
Our existing methods and tools already handled some aspects of unbalanced 
schedules and alternate sites, but additional work was needed to fully 
accommodate the 2020 reality.
 
In addition, the mere fact that the season was so short introduced another 
element.  Some of the raw park factors for 2020 were very, very extreme 
because of the small sample sizes.  Most visible were raw triples factors 
that ranged from zero to well over 700. 

We've never considered a 162-game season to be a large enough sample for park 
factors, so we've always blended current year park data with data from recent 
seasons to get a more accurate picture and smooth out the factors.  That was 
even more essential with the much shorter 2020 schedule. 

When less is not more 
---------------------

Another well-established baseball number -- the 162-game season -- fell 
victim to the pandemic this year.  The 60-game schedule didn't just mean that 
fewer games were played and that each of those games carried more weight in 
deciding who qualified for the postseason.  It also meant that our data-
driven methods for rating players had a lot less data to work with.
 
We noted earlier that we had to update our definition of "late innings" to 
account for seven-inning games when compiling data for our Clutch and Jam 
ratings.  But that was only half the challenge.  Even with the 5th and 6th 
innings included as "late" in seven-inning games, not a single hitter had 
enough late/close plate appearances to earn a top clutch rating by our old 
standards.
 
We therefore took some time to carefully assess how much we could lower that 
playing-time threshold to appropriately identify clutch hitters in 2020.  
Simply prorating the normal full-season standard to 60 games would have 
brought it so low that we'd be giving out these ratings based on random 
fluctuations in performance over tiny samples.
 
We believe we arrived at a very sound solution for both batters and 
pitchers.  You won't see quite as many top Clutch and Jam ratings as in a 
full season, but there's still a good number of deserving recipients.
 
For several other types of ratings, we had to supplement our data-driven 
methods for many players because they simply didn't have enough opportunity 
to demonstrate their abilities in such a short season.
 
This isn't new.  When rating players with limited playing time in any season, 
we don't just rely on the data for that season.  If a player's numbers are 
above average for base running, but they only had two running opportunities 
in the season, we don't consider that to be enough evidence to justify a good 
rating.  We would also consider other information about the player -- data 
from prior seasons, minor-league stats, position, age, injury history, and so 
on.
 
So the process of rating guys who didn't play much was not new to us.  What 
was new was the larger number of players with small amounts of playing time.
 
Was a sunny day, not a cloud was in the sky
-------------------------------------------
 
Most baseball seasons, in this hemisphere anyway, are played in a mix of 
early spring weather (cool, wet, an outside chance of snow), late spring and 
early summer weather (very nice!), peak summer weather (hot and muggy), and 
early fall weather (also very nice). 

Not so this year.  All the games were played between late July and late 
September.  So the average temperatures, temperature variations, rain 
frequencies, and wind patterns in our park ratings are a little different 
this year.
 
Fashionably late to the party 
-----------------------------

Another oddity of the 2020 season was the appearance of four players in the 
postseason who did not play at all in the regular season.  We chose to 
include these players so you could use them in DMB postseason games.  In 
fact, you can use them in regular season games if you want.
 
In each case, their stat lines are all zeroes because we didn't want to 
clutter up the real-life batting, pitching, and other reports with projected 
stats or something else.  This way, the team and league totals in DMB's 
reports reflect what actually happened in the real season.
 
But we did take the time to rate these players as accurately as possible 
given what we know about them.  In other words, don't take their all-zero 
stat lines as a sign they're unrated.  They do have realistic batting and 
pitching event tables and all the other ratings they need to participate in 
DMB games. 

Three of them -- C David Frietas of Milwaukee, RF Alex Kirilloff of 
Minnesota, and P Shane McClanahan of Tampa Bay -- were rated as they were in 
our 2020 Projection Database.  The fourth, P Ryan Weathers of San Diego, was 
rated as a replacement-level pitcher. 

For openers
-----------
 
We spent a lot of time studying the usage patterns of relievers who were used 
occasionally as starting pitchers.  This is an evolving strategy in modern 
baseball, so we feel the definition of an "opener" is still in flux.
 
For example, a team could have a bullpen day where five or six relievers are 
expected to pitch an inning or two each.  Or a team could piggy-back two 
starting pitchers, each throwing three or four innings if they don't get 
knocked out sooner.  Or a reliever could pitch the first inning or two and 
then hand the ball to a starter for the rest of the game.
 
Add these new approaches to other things that have been part of baseball for 
ages -- the swing man, an occasional emergency start by a reliever when the 
starter comes up lame during warmups, the gradual build-up of innings from a 
reliever who is being stretched out to become a starter -- and it can be hard 
to tell when someone is deserving of a starting pitcher rating.
 
In DMB 11, our approach to "openers" was to leave them without Start 
Durability ratings and treat them all as having the default durability of an 
unrated starter.  This would allow them to toss 30-40 pitches in a modern era 
before starting to tire.
 
In DMB 12, we decided it would be better to treat these outings as relief 
appearances for fatigue purposes.  Relievers who start games will be able to 
throw the same number of pitches as a starter as if they were brought in as a 
reliever in that game.  The number is based on their Relief Durability rating 
and how much they had been used in recent days.  As a result, a long reliever 
with an Excellent relief rating would be able to throw 55+ pitches before 
tiring, while another pitcher with a Fair rating would be much more limited.
 
20/20 vision
------------
 
During our work on the 2020 season database and the DMB 12 upgrade, we often 
wondered how much of what we've seen in 2020 might never be seen again.  It's 
always hard to predict the future, and perhaps especially tough right now, 
but here are a few thoughts about ways in which 2020 might be a one-off and 
ways it might shed light on what is to come.
 
Can we expect to see seven-inning games for double-headers in a normal year?  
Probably not, but if concerns about pace of play continue to be a driving 
force in the game, maybe.
 
What about the automatic runners in extra innings?  That seems more likely
to us, but who knows?.
 
In 2019, baseball announced that there would be limits on using position 
players as pitchers for the 2020 season and beyond. 

The new rule stated that position players would not be allowed to pitch 
unless one team is ahead by six or more runs or the game goes into extra 
innings.  This required a formal definition of a two-way player who would be 
exempt from these restrictions, but we believe it might take some time for 
the authorities to settle on a workable set of rules around these 
designations.
 
Those restrictions were not enforced in 2020, but we added support for them 
to DMB 12 in case they do go into effect in the near future.  If you choose 
to activate this rule for your league, any player with a role of Batter can 
only be used under these restrictions.  Any player whose role is Pitcher or 
Dual can pitch at any time.
 
For DMB 12, we also expanded the manager profiles to permit longer lists of 
pitchers and players in various roles.  Among other things, DMB is now set up 
to handle six- or seven-man rotations in the event that big-league teams go 
that way.  Or if you want to try that in your DMB leagues.
 
Will the Designated Hitter rule continue to be used for both leagues?  Hard 
to say.  Fortunately, DMB has been able to handle that since it debuted in 
1987, so we're ready for this either way. 
