1959 old house backyard lighting switch question.

Hello, and thanks if you know the answer. I have an old house and it has flood lights in the backyard that light up the lawn, which is nice. It seems to be on the same circuit as a side door light which i put a motion security light in it's place. Inside the house where the switches are, there are two dual pole switches (standard). It looks like there are two strands of nomex? that go into the switch box. on the left is one set that has red, blk, white wires. The wire set coming in on the right is Blk, and white only. The left i assumed were hot from the breaker and the right going to the light fixtures. When both light switches are off, left black is hot, left red is hot, left white is pigtailed to the right white wire. Right black i assume goes to the light fixture. The red hot from left switch is hooked up to the lower pole on right switch. The wires are hooked up like this picture. When right switch is on, left off, both the door security light and backyard lights function. When right is on, left is on, both the security light and backyard floods are on. When right is off, left is on, nothings on. And of course when both are off, lights are off. Attachment 39034 (http://www.doityourself.com/forum/attachments/lighting-light-fixtures-ceiling-exhaust-fans/39034-1959-old-house-backyard-lighting-switch-question-switch.jpg) oh i would like one switch to control the security light and the other to control the backyard light as i don't want the floods to be on constantly, but not sure what wires are what. The left again seems to be power from the breaker, red is hot, blk is hot till the switch is on, then both red/blk seem to have low power as it's not detected on my no contact pwr detector. When the right switch is on, all 4 wires are powered. I have no clue, works fine with just the right switch on but it powers both floods and security light for side door. Any ideas? thanks.