Alternative to alphabetic round ?

Why not encourage them to collaborate, and to come up with a joint plan for the next working day which gets them closer to their Sprint Goal?

I suggest you quit treating it as a "daily meeting" where everyone gives an update and start treating it as an event where the purpose is for the those Developers working in the Sprint to adjust their plan for meeting the Sprint Goal based upon the information they have learned since the last time they that gathered for that purpose. 

Honestly, it should be more of a discussion about the work the team is going to do that day than any kind of meeting.  The only "agenda" is to agree upon their plan until they gather again to work on accomplishing the Sprint Goal.

Hi Philippe, I assume you have taken on the Scrum Master accountability within this Scrum Team?

The Daily Scrum is for and by the Developers. They can use any format they like, so long as it focuses on progress on the Sprint Goal and making their plan for the next 24 hours to make more progress.

As Scrum Master, your accountabilities include:

• Ensuring that all Scrum events take place and are positive, productive, and kept within the timebox.

This may involve teaching or coaching or offering guidance to help Developers in staying within the timebox or having a productive Event. It doesn't involve calling on everyone, one by one, to provide a status update. 

Building off of what Ian and Daniel have already shared, the focus is on Developers collaborating on a plan to make more progress towards the Sprint Goal. Reinforcing this purpose with them is something you could do instead and then make space for them to self-manage and determine what works best for them.

A complimentary approach like the G.R.O.W coaching model may be something you could share with them. It focuses on Goal (Sprint Goal in this case), Reality (progress towards Sprint Goal), Options (collaborative discussion), Way forward (plan for the day).

ok, I was just asking for original ideas 

the scrum master at my previous job tried from time to time to find original ways to pick people randomly or a new app to draw postits on a virtual board

just to avoid routine and to break the monotone "every body's turn" , well, routine 

things like that

I quit trying to come up with original ideas.  As a Scrum Master I instead starting focusing on helping the Developers understand the reason for the event and the benefit it brings them.  After they start to understand that, there usually isn't a need for someone to call on people.  They get together, they start talking about how they plan to proceed and in 15 minutes or less, they are done. 

For me, the reason I didn't give a direct answer to your question, and will not again, is because by encouraging the behavior of only talking to when you have been called upon is counter productive to the reason and benefit of the Daily Scrum. Also, it goes against the concept of self-organization.  Let the Developers decide how they want to handle the Daily Scrum.  It is their event.  As a Scrum Master, we are not even expected to attend and absolutely not expected to participate in any way unless we are actually contributing to the Developer effort. 

"As a Scrum Master, we are not even expected to attend and absolutely not expected to participate in any way unless we are actually contributing to the Developer effort."

really, anyway here the SM is also a dev :-)

thanks anyway for your help