If the anomalous spike appears in both modern and wild, then there is no doubt that they are bots. That just means your analysis methodology is on track.

If, as you say, they are Splinterlands bots, they are not a problem, but at the end of the day they are bots, and it shows that good or bad bots can be identified with this methodology.

What can be very important is that the battle data you are using is updated, because the last 50 battles could include data from months ago when bots were still allowed in both formats.

Even if you can't pull battle data from the Splinterlands servers, you might want to create your own script to get that data firsthand.

It occurs to me that you could create your own version of a crawler and in this way obtain first-hand and permanently updated data. For example, you could create a trigger with your own account by starting a battle. Next, you read your battle history to find the name of the user you just battled. You use this user as a starting point for your crawler, reading the battle history of said user. Here you define what your analysis time window will be, let's say 24 hours. Thus, you get from that user's history the battles of the last 24 hours as well as the users with whom he battled. With each one of those user you repeat the same procedure and "Voilà", you get in theory all the players who have battled in that format during the last 24 hours.

The advantages of using a crawler is that you get completely updated data, which you can save in a database for future analysis. The disadvantage is that you need to keep the script running permanently or with a crontab that executes it at a specific time.

Finally, thinking about the spikes that occur at the end of the timeline, I realize that this data may be obfuscated because Splinterlands automatically submits the teams when the time ends. But even so, I am convinced that this area is where the bots are most likely to be found...