At Cousimbert, not far from Fribourg in Switzerland, Pirmin Bertle has put up Drop a line, ~8C+, his most difficult boulder problem to date.

After having all but retired from climbing due to injuries and bone marrow edema, Pirmin Bertle slowly began training again without any expectations. Quickly, he got better, and soon he was back on the same level as before the problems. Now a lot lighter, he could continue improving and, as he puts it, "break through to the next level".

Now, he has made the first ascent of a project he has worked on for eight months. Drop a line is a traverse, but as far as I understand, the grade is not a traverse grade. At 8C+, this would mean it's a contender for the hardest problem in the world, but there is a "but": 

In the recent past I have launched several high graded boulders and routes that claim from their appearance to be among the hardest in the world. They are not far from it, but they are nothing in comparison to what the strong young guns have done in the last years. I decided to grade them like this anyway. I have my reasons. I will explain.

On the other hand, Pirmin also says he needed way less time to repeat 8B's at Targassone than he had to spend on his own problems. A couple of hours compared to several days. So...it doesn't seem entirely clear, does it?

Pirmin Bertle is sponsored by: Maiday