Best Blowout Support Event until July 04.  

According to the Japanese 散歩道 site, the significance of high ATK Rating (AR) and DEF Rating (DR) is reduced in v2.5.13.

An AR60 attacker used to deal 200% damage to a DR50 defender, now the damage is reduced to 155%. Likewise, a DR60 defender used to take no damage from a AR50 attacker, but now he takes 45% damage.

The chance of an attack missing the target has also been reduced from 4% to 2% per difference.

A bit of an old news... but I find the table rather useful, so I stole it. :p