DApp Transactions Analysis: Etheroll suspicious gambler

by Maxim Odegov, Anatoli Belchikov, Serge Nedashkovsky

Recently we have analyzed players’ transactions on dice2win casino and found a system of interconnected addresses that have placed more than half of all bets. Having found this mechanism, we decided to check if the same cases exist in other DApps related to bets. Therefore, we analyzed the interconnections between Etheroll players in the same way.

Game mechanics

Here are the steps how Etheroll bets are placed:

1. A user calls the playerRollDice method of Etheroll contract with the parameter rollUnder. This parameter is used in the contract to define the winning probability and the size of the prize.
2. From the method rollUnder the contract calls Oraclize API to get a random number from random.org.
3. The result, received from Oraclize, is processed with the method __callback, which checks if the bet has won. If it wins, the contract sends a reward to the player address, otherwise the player gets 1 Wei.

As you can see from the description, the main feature that distinguishes Etheroll from other services is the usage of random.org through Oraclize, as it guarantees the randomness of numbers used to define the outcome of the bet.

General statistics

In Etheroll 872 players have placed bets, the number of bets equals 75,473. An average bet is 1.15 ETH, the total amount of bets is 86,936 ETH. Etheroll turnover displayed in figure 1.

Figure 1. Etheroll overall amount of bets over time

The total amount of bets by dates 92 out of 872 players have placed bets over 100 ETH each. The amount of these bets equals 92.1% (80,074 ETH). Figure 2 represents the proportions between different metrics for top addresses and for rest of them.

Figure 2. Dice2Win overall bet volume and amount for players from top players and the rest of them

Suspicious addresses

Analyzing the graph on incoming players’ transactions we have found the same case as in dice2win. We have detected a large connected component consisting of 354 addresses, 126 of which are Etheroll players. You can see the visualization of this graph in figure 3.

Interestingly, the graph shows that Ethereum senders in Etheroll have more receivers than dice2win ones.

Figure 3. Suspicious players and their ties in relation with the rest of casino players’ interconnections

The amount of bets made by the addresses of this group is smaller than in dice2win where the amount of bets made by a suspicious group reached more than half of the total bet (52.1%), but it is still significant and equals 36.9% (32,065 ETH). The number of bets was also low and equals 40.6% (30,629). These proportions represented in figure 4. Figures 5 and 6 shows how the amount and number of bets are distributed over time.

Figure 4. Etheroll overall volume and number of bets for common and suspicious players

Figure 5. Amount of bets for common and suspicious players over time

Figure 6. Number of bets for common and suspicious players over time

It also worth noting that the players included into the group of suspicious addresses take the first two places in the list of top 10 players (see table 1). The amount of bets placed by these players is more than half amount of total bets placed by suspicious players.

Table 1. TOP-10 players and their participation in rigged turnover