I think the chart (the one on the left) is just for general reference only. I tried 3 brands of Vandoren reeds: Traditional, Java and ZZ.
From the chart, Traditional 2 has the same strength as Java 2.5 and ZZ 2.5
But acutally, I found that Vandoren 2 is hardest, followed by Java 2.5 and then ZZ 2.5
Of course, this may be subjective and may be affected by the moutpiece that one uses.
From the chart, Traditional 2 has the same strength as Java 2.5 and ZZ 2.5
But acutally, I found that Vandoren 2 is hardest, followed by Java 2.5 and then ZZ 2.5
Of course, this may be subjective and may be affected by the moutpiece that one uses.