S11 probability endpoint after ad unlock

[antebrl]

Hi, first of all — amazing project. Thanks a lot for your work!

I'm trying to scrape the S11 probability without having premium access. As expected, the prob field is missing from the response for non-premium users.

However, since the latest update there's the option to watch an ad to reveal the probabilities for your own squad. That made me wonder: which endpoint does the app call to retrieve the probabilities after the ad has been watched?

Maybe you already know or could take a quick look.

Otherwise, I'd also be happy to test it myself if you could share how you're currently sniffing the requests in your setup.

[simonsagstetter]

Hi @antebrl,

I have been asked this question many times before. Previously, this probability was provided by an external service (Ligainsider Premium). This is no longer the case, although I no longer play Kickbase myself and therefore do not know what the current situation looks like in the UI.

However, I cannot imagine that the source of the data has changed. Perhaps Kickbase has integrated Ligainsider's API or a single endpoint into its API through their partnership. Since the probabilities are created editorially by ligainsider, there is probably great interest in ensuring that this remains a premium feature.

I know that Kickbase works with Spring Boot in the backend and can probably roll out and display fields based on roles or even return completely different DTOs.
Theoretically, temporary roles can also be assigned by viewing advertisements, which allow one-time access to the same endpoint with premium rights, thereby obtaining the probabilities.

I found the field in the model domain and it is called "startingElevenProbability". It can be found in the API under the serialized name "prob". Theoretically, it should appear under one of the following endpoints:

GET /v4/leagues/{leagueId}/managers/{managerId}/squad

GET /v4/leagues/{leagueId}/lineup

If not, then this is probably being prevented intentionally.

I'm sorry I can't help you any further with that.

[antebrl]

Thanks for this information, @simonsagstetter!

I only started playing last year, so I’m not sure how things were before. However, I’ve noticed that LigaInsider and Kickbase sometimes have different predictions, so I could imagine that Kickbase might have switched to managing the predictions themselves.

The endpoints you mentioned do indeed return the prob field, but only if the requesting user has a premium account.

In the app, there is also an option to watch an ad to view the probabilities for your own team.
I’m planning to take a closer look at which request is sent after watching an ad, maybe it includes some kind of token.

Is there any information on how you collected the endpoints? Did you sniff the traffic using Wireshark? I assume you would need to install a custom CA certificate to decrypt the requests. Or did you reverse engineer the APK itself?

[simonsagstetter]

Hi @antebrl,

It is an interesting observation that the probability values differ. Perhaps Kickbase calculates additional factors or has developed its own calculation method. Regardless, as you mentioned, this probability is only available to premium users.

As far as unlocking Premium via advertising in the short term is concerned, I haven't been able to find any references to this in the current v4 API. There is a /promotion endpoint, but I don't think it has anything to do with this. It could also be an existing endpoint from v1, v2, or v3.
Sniffing the traffic would therefore probably be the best option. However, I know from experience that it is very difficult to intercept and decrypt HTTPS network traffic from Android or iOS phones using a man-in-the-middle proxy because the apps often check the root certificate for security reasons. If this cannot be verified, no network request is sent and it can even cause the app to simply log you out.

I would rather not discuss publicly how exactly I obtained the information to create this API. I would also advise you not to go into too much detail, as this could violate Kickbase's terms and conditions and licensing rights.
The official version is that all endpoints were found through trial and error.

As a software developer, I can say that it is theoretically possible to decompile software and obtain the source code, even if it does not correspond to the original source code in any way, but rather to a readable version of the compiled package. For example, there are open source projects such as the ‘jadx decompiler’, which compiles Java source code from apk files. For iOS/Mac OS sources, there is Hopper or IDA Pro.

I hope this has been helpful.