Chatter Plots: Openers in WCS Americas

Published on 05/03/2019 05:02 PDT by Firnafth


Welcome back to Chatter Plots. Today we bring an interactive and exploratory tool, visualising early build orders used in WCS Winter Americas 2019. Build order here is recorded so far as the first four non-supply buildings.


Included in this article are two variations:
1) Race overview - select a race and see the aggregate early build order view

2) Matchup overview - select a race and opponents races to compare differences between matchups



What does this tool show me?


This chart tries to visualise early build order prominence and diversity within WCS Americas 2019. This tool specifically visualises the first four non-supply buildings that are built by each player in each game and in the order they decide to build them in. 


For example, 58% of Zergs followed the exact build order of Hatchery – Extractor – Spawning Pool – Hatchery. Moreover, only 2% of Zergs went double hatchery opening. 



How do I read this chart?


This chart is known as a sankey diagram and shows the proportional flow between the first, second, third and fourth building that was built. 


There are 4 columns, which represent the order in which a building was made. Each column will be split into the different buildings that were made in that phase. The size of these partitions/bars is the proportion of each building that was created. For example, 3% of Protosses built a Nexus as their first building.


The flow between each column represents 2 things:


1) The size of the flow indicates the number of times that team chose to build that type building after creating another type. For example, how many times did they chose to build assimilator as their third option and then chose cyber core as their fourth option?


2) You can also see the breakdown of the different combinations that make up one whole stream, from 1 to 4. For example, we can see than in 19 matches, Hatchery was built as the second building with Extractor as third. However, we can break this down further and see that:

  • 7 of those followed the sequence: Spawning Pool – Hatchery – Extractor – Hatchery
  • 4 of those followed the sequence: Spawning Pool – Hatchery – Extractor – Extractor
  • 3 of those followed the sequence: Spawning Pool – Hatchery – Extractor – Roach Warren
  • 2 of those followed the sequence: Spawning Pool – Hatchery – Extractor – Evo Chamber
  • 1 of those followed the sequence: Spawning Pool – Hatchery – Extractor – Baneling Nest

  • 2 of those followed the sequence: Hatchery – Hatchery – Extractor – Spawning Pool


You can also update the color legend to visually aid analysing the flow of one particular building phase. For example, when the color legend is set “Third Building”, you can trace all sets of first two buildings which were constructed before that third building and what the following fourth buildings were from that third building.



How do I use this chart?


Now that we understand what this chart is telling us, let’s interact with it to get the most insight from the visualisation.


The race icon on the left-hand side will act as a filter for the sankey diagram – it will only show the streams relevant to that race.


Set the color legend to focus on which phase of the build you want to analyse.


Hover over each of the bars to see the number of matches and the proportion of buildings that constituted that phase.


Hover over the stream to see the proportion of matches that built in that order. For example, if you hover over a stream between column 1 and 2, you can see the proportion of matches that chose to construct those two opening buildings in that order. 


Hover over the stream also includes the proportion of matches for an exact build, specific sequence of one to four building; however, you should set the color legend to ‘Fourth Building’ to get the most visibility on exact builds.


Filter a phase if you want to refine and simplify your analysis.

Additionally, in the matchup comparison, Ctrl + Click opponents race to multi-select races to compare.




Data Source


We collected data by watching VODs of all games played for 2019 WCS Americas Winter (n=235 games). For each game, we notated the players, matchup, winner, and game duration; during the games we also notated the first four nonsupply buildings built by each player and any proxies attempted; and we tallied all attacks, their initiator, whether the attack was harassment or not, and its general unit composition as well as the unit composition used to defend against it.


For fully detailed methods, see this document.

For raw data, see this spreadsheet.