Kempelen wrote:Hello,

I am having problem implementing multipv. Maybe my english is not good to undestand this, but can someone explain me what it is in bold:

* multipv

this for the multi pv mode.

for the best move/pv add "multipv 1" in the string when you send the pv.

**in k-best mode always send all k variants in k strings together.**

Also If I find multipv 3 better than 2 for current depth, must I sort all pv by score and send them again, or can I send them as they are found... must I change the multipv number for a variant at any place?

if not, does the gui usually sort them?

Can someone put me an example please?

Thanks in advance

Fermin

* multipv

this for the multi pv mode.

for the best move/pv add "multipv 1" in the string when you send the pv.

in k-best mode always send all k variants in k strings together.

My understanding is, say k is 4 then send like

multipv 1 depth 1 score cp 4 pv e2e4

multipv 2 depth 1 score cp 5 pv g1f3

multipv 3 depth 1 score cp 6 pv d2d4

multipv 4 depth 1 score cp 1 pv b1c3

Together would mean that you have to send this successively.

The way I do it is something like,

1. Say we are at depth 1, search a root move, if I get a move save the move, and score.

2. Search the root again but this time ignore the move I saved in step 1.

If you get a move save it again.

3. Search the root again but this time ignore the moves saved in steps 1 and 2. Once you get the move save it again.

4. Do the same above when searching the 4th best move.

5. Once you completed the requested k best move, you are now ready to send your multi pv. You may sort the pv lines based on score before sending.

I tried Fritz 13, and you can send the pv even without sorting, Fritz 13 will sort it for you. Arena 3 will not sort.

6. Next increase the depth to 2 and do the typical steps in 1 to 5.

7. Next at depth 3 and so on.

In my case I sort the saved pv based on the score before sending.