A colourful #WOW2022 challenge this week set by Kyle Yetter and using his favourite data – Baseball. Let’s jump straight in.

Building the required calculations

First up we need to calculate the core measure the viz is based on – % of wins

Win %

SUM([Wins])/SUM([Games])

I formatted this to 3 decimal places, then applied a custom number format to remove the leading 0 (custom number format looks like ,##.000;-#,##.000).

We also need to know the number of losses as this is part of the tooltip.

Losses

SUM([Games]) – SUM([Wins])

Let’s pop all these out into a table (I formatted all the whole numbers to display without any decimal places).

The viz however isn’t plotting the actual Win%, it’s plotting the difference from 50% (or 0.5), so values less than 50% are negative and those above are positive.

Plot Postion

[Win %] – 0.5

And we also need to know whether the Win% is above 50% or not

Above 50%

[Win %]>0.5

Pop these out onto the table too

The viz also displays the overall Win% for each team, and also uses this to sort the data. As it is used for sorting, we need to use an LoD calculation (rather than a table calculation).

Overall Win% LOD

{FIXED [Team]:SUM([Wins])} / {FIXED [Team]: SUM([Games])}

for each team, get the total wins, and divide by the total games for the team. Format this to 3 dp with no leading 0 as before.

pop this into the view (you’ll see it’s the same value for each row for a single team), and then apply a Sort on the Team field to sort descending by the Overeall Win% LOD.

Now we have the data sorted, we can create the fields needed to build the trellis chart.

I have already blogged challenges relating to trellis charts / small multiples (see here) which in turn reference other blogs in the community, so I’m not going to go into all the details. We just need to build two calculated fields to identify which row and which column each Team will sit in. The table is fixed at 6 columns wide as the data wea re using is static. Some solutions work with a more dynamic layout depending on how many entities you need to display. We’re keeping things simpler.

Cols

FLOAT(INT((INDEX()-1)%6))

Rows

FLOAT(INT((INDEX()-1)/6))

Add both these fields to the table as discrete dimensions (blue pills), and as they are both table calculations, set them both to Compute Using – > Team.

Building the Core Viz

On a new sheet, add Cols to Columns as discrete dimension, Rows to Rows as discrete dimension and Team to Detail. Set both Rows and Cols to Compute Using Team.

Add Year as continuous (green) pill to Columns and Plot Position to Rows and change the mark type to Bar and reduce the size. Sort the Team field based on Overall Win% LOD descending.

Add Wins, Losses, and Win% to the Tooltip shelf and adjust the tooltip to display as required. Add Above 50% to the Colour shelf (you may need to readjust the size). Leave the colours as they are for now – we’ll deal with this later.

Adding the labels

Create a new calculated field

Dummy Plot

FLOAT(IF [Year]=2000 OR Year = 2020 THEN 0.35 END)

This is basically going to position a mark at height 0.35 but only if the year is either 2000 or 2020. These values were all just based on a bit of trial and error as to what worked to get the desired result.

Also create a field

LABEL:Team

IF [Year]=2000 THEN [Team] END

and

LABEL:Win%

IF [Year]=2020 THEN [Overall Win % LOD] END

format this to 3dp and exclude the leading 0.

Add Dummy Plot onto Rows and change the mark type of this measure to circle. Amend the Tooltip of this marks card so it’s empty.

Add LABEL:TEAM and LABEL:Win% to the Label shelf, and adjust the label so both fields sit side by side (only 1 value will only ever actually display). Adjust the table calculation of both the Rows and Cols pills so they now compute using both the Team and the LABEL:Team fields.

Adjust the alignment of the labels so they are positioned bottom centre. Set the font colour to match mark colour and bold.

Then reduce the size of the circle mark to as small as possible, reduce the opacity of the mark colour to 0.

Now make the chart dual axis and synchronise the axis. Remove the Measure Names field that has automatically been added to the All marks card.

Hide all the headers and axis (uncheck Show Header), remove all grid lines, zero line, axis rulers.

Hide the null indicator (bottom right).

Colouring by Team

Copy the colour palette text Kyle provided into your preferences.tps file (usually located in the My Tableau Repository directory). For more information on working with custom colour palettes see this Tableau help article.

You’ll need to save your workbook and re-open for the new palette to be available for use.

In order to prevent having to manually set all the colours (and believe me you don’t want to do this!), perform the following steps in order

• Add Team to also be on the Colour shelf. Click on the 3 dots (…) that are to the left of the Team pill on the All marks card, and change it to Colour. This means there are now 2 fields on colour. Move the Team field so it is listed above the Above 50% pill. This means your colour legend should be listed as <Team>, <True|False>

• Adjust the Sort of the Above 50% pill, so it is manually sorted to list True before False.

• Now change the Sort on the Team field so it is sorted alphabetically ascending instead. This will cause the viz to change its sort order, but don’t worry for now. It also changes the list on the colour legend, so ARI, True is listed first then ARI, False etc.

• Now edit the Colour Legend and select the new MLB Team Colours palette we added. Click the Assign Palette button to automatically assign the colours. As we’ve made sure the entries listed are in the right order, they should get the correct colours.

• Change the Sort on the Team field back to be based on Overall Win% LOD descending

And that should be it. You can now add the viz to a dashboard and publish. My published version is here.

Happy vizzin’!

Donna