An analysis of calculations used by DPR to determine future “needed” fields shows DPR overestimates the demand for Adult Diamond fields by 26-55%.

The analysis also revealed some of those calculations weren’t even based on the right numbers, causing DPR to present a deficit in 30 years when there is actually a significant surplus -- even using the inflated calculations.

This raises major questions:

This is based on review of the adult diamond field estimates (DPR FOIA) and actual adult reservation data (Open Data Portal).

DPR Estimates

Let’s first present the numbers and calculations used by DPR to estimate the number of hours needed for various types of fields. (source: POPS Field Estimatev3.xlsx)

The DPR estimates for adult-size diamond fields is based on the following calculations (taken from sheet “Diamond Review”, cell C27):

(# of Teams)         x (Average hours per team each week)         x (weeks in a season)

Let’s now look at the numbers used by DPR:

Number of adult softball teams:         150 (111 DPR leagues, 38 social leagues, 2 LL Challengers)

                        195 (144 DPR leagues, 49 social leagues, 2 LL Challengers)

Seasonal Weeks:        13

Weekly Game Hours:        1 “softball is usually a double header of a 1 hr game”

Note that “Weekly Hours” in this context is amount of game hours per week, per team. So for a one hour game played by two teams, that’s 30 minutes allocated to each team. DPR’s use of 1 hour per week is based on each team playing two one-hour games per week.

Using these numbers, DPR estimates 1954.4 hours of needed adult diamond field time:

(# of Teams)         x (Average hours per team each week)         x (weeks in a season)

150        x 1        x 13        =        1,950


Note that DPR’s number of 1954.4 hours is slightly different because their number of teams is actually a calculated number of 150.33846... For this analysis, we’ll use the simpler numbers.

DPR numbers versus correct numbers

Doing some basic research on DPR softball leagues and affiliate leagues shows that the team, game, and week numbers used as the basis for calculations are not actually correct:

So already we can see the estimates are off, as the calculation should have been based on a much lower number of weeks or hours/week:

(# of Teams)         x (Average hours per team each week)         x (weeks in a season)

111        x 1        x 9        =        999

38        x 0.5        x 13        =        247

2        x 1        x 7        =        14

                                =        1,260 total

Accurate estimates based on correct numbers

In fact, an accurate estimate would be based on actual games, with an allowance for weather.

(# of Teams)        x (Hours per game per team)        x (number of games)        = Game hours

111        x 0.5        x 18        = 999

62        x 0.5        x 8        = 248

2        x 1        x 7        = 14

                        = 1,261 total                

DPR consultants indicated 23% of Spring and 12% of Fall days are “days lost in some capacity to closed natural grass fields” (DPR), so we’ll add in 23% extra.

Game hours         + Average rainout hours        

1,261        + 290        = 1,551

DPR “Hours Needed” estimates are 26-55% higher than they should be

Using either the 1,261 number based on a more accurate figure of seasonal play or the 1,551 estimate based on game time and including weather variations, the 1,954 figure of “needed” hours presented by DPR is 403 to 693 hours higher than it should be based on actual schedules.

Comparison to actual reservations

For further analysis, we will compare these estimates to actual reservations on adult softball fields.

The following analysis focuses only on the DPR Adult League portion of the estimates because those reservations are  broken into individual 2-hour blocks. Each of these blocks correspond to a double-header of two games. The same analysis of “adult social” reservations is more difficult because social reservations are not all in 2 hour blocks representing a game. E.g. Fray will reserve 12 hours on a Sunday. And Zog will reserve 3 hours on a Thursday. So it is difficult to tell how many games or teams that represents.

Looking at actual reservation data (Open Data Portal) for 2017 shows

Each 2-hour reservation represents a double-header of two 1-hour games.

According to DPR, each team plays 18 games over 9 weeks. So dividing the number of games by 18 should indicate the number of games per teams. Since there are two teams per game, multiplying that by two should give the actual number of teams:





Games per Team

(Games / 18)


(Games per Team) *2

Spring 2016





Fall 2016





Spring 2017





Fall 2017





The 106 teams for Spring 2016 and 94 for Fall 2016 do not match the numbers of 111 for Spring and 144 for Fall used in POPS calculations:

So both numbers appear to be higher than actual. But how can the Fall numbers be so off?

Looking at the POPS calculations, we see why: The Fall 2016 adult diamond “teams” number of 144 is copied from the future estimate for Spring 2045.

The numbers that were intended to be used for Fall 2016 are in another DPR spreadsheet, showing Adult DPR leagues is 102:

This Fall 2016 DPR Adult diamond team number of 102 number is still 8% higher than the 94 teams that would correspond to the actual Fall 2016 reservation data. However, even using the inflated number of 102 teams and also even using the calculations shown above to be inflated 40-50%, changes the incorrect minor predicted deficit of 141 hours in 2045:

to a surplus of 695 hours: (The below chart is what the calculations should be)