The Legacy of Petrus

The Petrus method was created in 1981 and so much of the method can be seen in almost every other method that we have today. Below are some of the creations or popularizations that came from the Petrus method.

Innovations and Popularizations​

Blockbuilding: While in the late 70s to early 80s other methods were using cross and F2L, corners first, or edges first, Lars Petrus was doing something different. His idea was to build groups of pieces and continually expand to the end of the solve while maintaining freedom of movement. This freedom of movement leads to more efficient solutions. Look at how many methods are now based on blockbuilding.

Edge Orientation: The second big realization that Lars Petrus had was to flip the edges after solving the 2x2x3 in such a way that the rest of the solve is easy and fast to perform, look-ahead is improved, and the number of last layer cases is reduced.

2-Gen: A very popular goal now, intentionally reducing to RU ergonomics originated in the Petrus method. Flipping the edges so that they are oriented with the U and R centers reduces to a very ergonomic right side block. Now within method development we have seen this idea extended further with early corner permutation to allow for 2-Gen to be used for a longer duration of the solve.

ZBLL: Orienting the edges during the first two layers reduces the number of last layer cases from 3915 to 493. This means that it is easier to learn algorithms for all of the cases and solve the last layer in a single step. ZBLL is currently one of the big goals for Petrus, CFOP, and ZZ users.

Since the Petrus method’s creation in 1981 and its popularization once Lars posted his website in 1997, there have been many new methods influenced by Petrus and existing methods altered to include Petrus techniques. Below are just a few among the many that could be mentioned.

Influences​

CFOP: In the early 2000s, CFOP users saw the potential that an all edges oriented last layer had. They also saw the algorithms that Bernard Helmstetter had generated for the Petrus method which solved the last layer in a single step. One popular idea during those years was to use something called ZBLS to orient the last layer edges while solving the final F2L pair then use Bernard Helmstetter’s last layer algorithms. Nowadays CFOP users often use edge control to try to ensure that the last layer has all of the edges oriented.

Roux: Gilles Roux was a Petrus user before creating his own method. He once told me that he had the idea for the Roux method while using the MU based EPLLs with the Petrus method. So looking at the fact that Petrus has a 2x2x3 block on the left and a 1x2x3 block on the right and combining that with the use of MU EPLLs shows the connection between the two methods.

ZZ: Edge orientation is the foundation of ZZ. Using EO to reduce the moveset to RUL, the number of blockbuilding and F2L pair states, and the number of LL states is a clear influence by Petrus.

APB: Completely based upon Petrus. It involves alternate 2x2x3 building techniques and the EO + RB steps are performed in an algorithmic way.

Petrus has always been thought of as slightly behind other methods. But there also were always users who tried to prove the method. However, things greatly changed in the past few years. One popular YouTuber uploaded a video claiming that Petrus isn’t as good as others, causing a big change in the community. The opinion went from “Petrus is cool, but unproven so we aren’t sure about the potential” to constant memes around the community of things like “Why would anyone even use Petrus?” and other negativity that I don’t want to mention here.

Petrus may be unproven for modern speedsolving, but that doesn’t mean that it can’t be as fast as other methods. It has also had a huge impact on almost every other method that exists. So much that the method, and Lars Petrus himself, deserves to be respected and recognized for the positive impacts on the community.