Official documentation for ansible: http://docs.ansible.com/ansible/intro_getting_started.html

[root@redis ~]# yum info ansible.noarch | grep Version
Version     : 2.2.0.0
[root@redis ~]# yum info ansible1.9.noarch | grep Version
Version     : 1.9.6

Note: older syntax (1.9.x) is compatible with ansible 2.2.x.
2.2.x syntax is NOT compatible with 1.9.x